CA1152063A - 3',4'-DIDEOXYKANAMYCIN A AND 1-N-((S)-.alpha.- HYDROXY-.omega.-AMINOALKANOLY) DERIVATIVES THEREOF - Google Patents

Abstract

ABSTRACT OF THE DISCLOSURE:
3',4'-Dideoxy derivative and 1-N-((S)-a-hydroxy-.omega.-aminoalkanoyl)-3',4'-dideoxy derivative of kanamycin A are now synthetized from kanamycin A and show a wider and/or higher antibacterial activity than the parent kanamycin A
so that they are useful in therapeutic treatment of infections by gram-negative and gram-positive bacteria, including drug-resistant strains thereof. The production of these new derivatives may be made by preparing a protected kanamycin A derivative having its 3'- and 4'-hydroxyl groups unprotected and having its all or substantially all other functional groups protected from the initial material, kanamycin A, sulfonylating the 3'- and 4'-hydroxyl groups, removing the 3'- and 4'-sulfonyloxy groups from the re-sulting 3',4'-di-sulfonic acid ester product to give a 3'-eno-kanamycin A derivative, hydrogenating the 3'-eno-kanamycin A derivative to saturate the 3',4'-unsaturated bond and to yield a protected 3',4'-dideoxykanamycin A
product, followed by removal of the remaining protective groups, and optionally further followed by 1-N-acylation of the 1-amino group of the resulting 3',4'-dideoxy-kanamycin A with an (S)-.alpha.-hydroxy-.omega.-aminoalkanoic acid or its reactive equivalent.

Description

~L~5Z¢~3 SU~ARY 0~ THE INVENTION:
This invention relate~ to new and useful derivatives of kanamycin A which are ~aluable as antibacterial a~ent, and also to the produc~ion of such new kanamycin A
derivatives. More particularly~ this invention relates to 3',4'-dideo~ykanamycin A and a l-N-(a-hydroxy- ~ -amino-alkanoyl) derivative thereof, especially l-N-(2-hydro~y-3-aminopropionyl)-3',4!'-dideoxykanamycin A and l-~-((S)-

2-hydro~y-4-aminobutyrvl)-3',4'-dideoxykanamycin A which are each a new compouncl, as well as an acid-addition salt of these new com~ounds.
This invention also relates to a process for the production of 3',4'-dicleoxykanamycin A and to a process for the production of the ]L-N-(a-hydroxy-~ -aminoalkanoyl)-~',4'-dideo~ykanamycin A. This invention further relates to theapplications of these new compounds aQ antibacterial a~ent.
BACKGROUND OF THE INVE~ION:
l. Field of the Invenltion This invention relates to novel chemicals which are useful as antibacteria:L agents and, more specifically, to aminoglycosides such as 3',4'-dideoxykanamycin A and deri-vatives thereof prepared by selectively acylating the l-amino function with an -hydroxy-~-aminoalkanoyl moiety.
2, ~escription of the Prior Art Kanamycins A and B were first described by Hamao Umezawa et al, as in U.S. 2,931,798,

3',4'-Dideoxykanamycin B was disclosed by Hamao Umezawa et al. in U.S. Reissue 28,647 (from 3,753,973) , ~;

~3L5~(;i 63 and additional processes for its preparation were given by H. Umezawa et al. in U.S. 4, 155,078 and U.S. 4,169,939 and in U.K. Spec'n 1,537,905 (pending U.S. application Serial No. 745,016 filed November 26, 1976, abstracted as Farmdoc 41695Y).
Hamao Umezawa e1: al. disclosed 3',4'-dideoxykanamycin C in U.S, 4,120,955, l-N-[~-Hydro~y~ aminoalkanoyl] derivatives of 3',4'-dideoxykanamycin B etc., were disclosed in U.S. 4,001,208 and corresponding derivatives of kanamycin A and B were dis-closed in U.S. 3,781,268, 3,886,139 and 3,904,597 with improved processes set forth in C~n~dian P~tent No~ lr030~961 issued May 9, 1978 and 1,021,329 issued November 22, 1977.
6'-N-Methyl-l-N--[~-hydroxy-~-aminoalkanoyl derivatives of 3',4'-dideoxykanamyc:in B were described by H. Umezawa et al. in U.S. 4,147,861.
l-N-[a-Hydroxy~ aminobutyryl]-6~-N-methyl derivatives of kanamycins A and B were descri~ed by Umezawa et al, in U.S. 4,170,642 a~d 4,001,208 respectively (and see also Farmdoc abstract 46482X).

Some of the preE~ent inventors, H. Umezawa et al have found that drug-resistant strains of gram-negative bacteria isolated from patients, resistant Staphylococcus aureus and Pseudomonas aeruginosa and some kinds of resistant bacteria produce an enzyme (phosphotransferase) which is capable of phosphorylat;ing ~'-hydro~yl group of kanamycin A, kanamycin B and other analogous aminoglycosidic antibiotics, and that these aminoglycosidic antibiotics can lose their antibacterial activity by phosphorylation of the 3'-hydro~yl group through the action of the pho9phorylating enzyme ("Science" Vol. 157, pages 1559-1561 (1967)). After this finding was obtained, e~tengive researches have been made about the mech~nism of resistance of bacteria to amino-glycosidic antibiotics~ At present, it is found that one or some of hydroxyl groups present in the aminoglycosidic antibiotic, such as hydro~yl groups at the 4'- and/or 2"-positions of the aminoglycoside molecule can be phosphorylated or adenylylated by a wide variety of resistant bacterial strains so that the parent amino-glycosidic antibiotic can lose the antibacterial activity.
Based on this finding, we already semi-synthetically prepared many semi-synthetic aminoglycosidic antibiotic derivatives which are active even a~ainst the resistant strains. Among the semi-synthetic aminoglycosidic antibiotic derivatives, 3',4'-dideo~ykanamycin B (see U.S. patent 3,753,973) is known under the general name "dibekacin" and is now used widely in therapeutic treatment of bacterial infectionq in clinics, because dibekacin is remarkably active against a wide variety of resistant bacteria.
It was very epochal to make the discovery that the removal of 3'- and 4'-hydro~yl groups from kanamycin ~, that is, the 3',4'-di-deo~ygenation of kanamycin B gives a semi-synthetic substance which does not lose the anti-bacterial activity of the parent material kanamycin ~ but rather attain an improved or modified antibacterial activity even again~t the resistant bacteria.

~;2~63 On the other hand, it wa~ known that butirosins which ~ere aminoglyco~idic antibiotics produced by a Bacillus species were active against some kanamycin- and ribostamycin- -resistant bacteria q`hese butirosins have been identified as 1-N-((S)-2-hydroxy_.4_aminobutyryl)-5-0-~-D-xylofuranosyl-or ribofuranosyl_neami.ne [see the ~etrahedron ~etters"
Vol. 28, pages 2617-2620 (1971)].
From comparison of the antibacterial activity of ribostamyc:in with that of butirosin B, it was di~covered the ($)-2-hydroxy-4-aminobutyryl substituent on l-amino group of butirosins has an important role in making ribostamycin highly ac.tive even against the resistant bacteria. From this d.iscovery, it was deduced that an aminoglycosidic antibi.otic can be imparted with an anti- .
bacterial activity aga.inst the resistant bacteria by introducing an aminoacyl group into the l-amino group of an aminoglycosidic antibiotic. After this discovery, the l-~J-aminoacylation ha~l been applied to a variety of amino-glycosidic antibiotic~l. A succe~sful application of the l-N-aminoacylation is e~emplified by amikacin (also termed a~ BB-E8), that is, 1-N-((S)-2-hydroxy-4-aminobutyryl)-kanamycin A (see the "IJournal of Antibiotic~" Vol. 25, pages 695-708 (1972); U.S. patent No. 3,781,268).
In spite of the\ presence of 3'- and 4'-hydroxyl groups in the amikacin molecule, amikacin cannot be in-activated by the kanamycin-resistant bacteria owing to that the 3'- and 4'-hydro~yl groups can neither be phosphorylated nor be adenylylated under the action of the l-N-((S)-2-hydro~y-4-aminobutyryl) substituent of amikacin. While, as amikac~n is applied much more frequently and widely in clinics, new type~ of the re~istant bacteria which are registant to amikacin are going to occur. In the most recent years, there have been made some reports to show that the 4'-hydroxyl group of amikacin is adenylylated by certain new strains of the resistant bacteria, and that the 3'-hydro~yl group of amikacin is phosphorylated (see the "Antimicrobial Agents and Che~otherapy~ page~3 619-624 (1977), for e~ample).
..
In view of the abo~e-mentioned facts and ob~er-vations, we expect tha-t if the 3'- and 4'-hydroxyl groups can be removed from kanamycin A, the 3',4'-dideo~ykanamycin A so possibly obtained will be active against the new types of the re~istant bacteria, too.
However, it has been confirmed experimentally that when kanamycin A is merely sub~ected to the method of de-o~ygenation comprising ~',4'-di-0-sulfonylation and sub-sequent treatment of the 3',4'-di-0-sulfonic acid ester with sodium iodide and zinc powder which was successfully applicable in the semi--synthesis of 3',4'-dideo~ykanamycin B, there cannot yet be obtained 3',4'-dideo~ykanamycin A
as e~pected. This is because the kanamycin A molecule contains 2'-hydro~yl group adjacent to the 3'-hydro~yl group thereof so that this 2'-hydro~yl ~roup can be sulfonylated concurrently to the sulfonylation of the 3'- and 4'-hydroxyl groups, with a consequence that the 2'~hydroxyl group once sulfonylated can be removed at the same time a~ when the removal of the sulfonylated 3'- and

4'-hydro~yl group~ i8 performed by treating with sodium iodide and zinc powder.
Accordingly, we have con~idered that 3',4'-dideo~y-kanamycin A cannot be synthetized from kanamycin A by applying thereto the same deo~ygenation method as the one which was adopted in the synthesis of 3',4'-dideo~ykanamycin B ~rom kanamycin B, unless we are not able to prepare and provide such a protected kanamycin A derivative which is to be subjected to the procedure of de-oxygenation as mentioned above and of which the 3'- and 4'-hydro~yl groups of kanamycin A remain in the unprotected state, while the neighboring 2'-hydro~yl groups as well as all the other hydroxyl groups and all the amino ~roups are e~isting in the protected or blocked state. However, no great differ-ence is observed between the 2'-, 3'- and 4'-hydro~yl groups of kanamycin A in respect of their reactivity, and hence it wa~ very difficult to find out any procedure by which the 2'-hydro~yl group can be protect~d with retaining the 3' and 4'-hydro~yl groups unblocked.
We have researched e~tensively in an attempt to provide such ~uitable kanamycin A derivative. As a result, we have now found that such a protected derivative of kanamycin A having 3'- and 4'-hydro~yl groups unblocked, having a protected or unprotected 2"-hydro~yl group and ~;2~;;63 having the other hydrc,~yl group~ (including 2'-hydroxyl group) as well a~ all the amino group~ blocked is prepared by means of a combinat;ion of an ingeniou~ choice of the nature o~ the hydro~y~.-protecting and amino-protecting groups employed, with an elaborate arrangment of the se~uence of the re~pec:ti~e ~tages of protecting each amino group and each k,ydroxyl groups, ln such a way that the 6'-amino group of kanamycin A which is the most re-active among the four amino groups of kanamycin A is at first blocked by an al.ko~ycarbonyl group, an aralkyloxy carbonyl group, especi.ally benzyloxycarbonyl group or an aryloxycarbonyl group known as one of the conventional amino-protecting groups; the 1-, 3- and 3"-amino groups of kanamycin A are then protected with a hydrocarbyl- .
sulfonyl group such a~ an alkylsulfonyl group, an aryl-sulfonyl group or aralkylsulfonyl group; the free 4'-hydroxyl group and the alkoxycarbonylated, aralkyloxy-carbonylated or arylo~ycarbonylated 6'-amino group are subsequently condensed with each other into the form of a cyclic carbamate by treatîn~ with e.g. sodium hydride, re~ulting in a ~imultaneous protection of the 4'-hydroxyl and 6'-amino groups; a pair of the 5-hydro~yl group and 2'-hydroxyl group are selectively and simultaneously blocked by introducing and bridging therebetween with a known divalent hydro~yl-protecting group such as an alkylidene group, 8pecially i~opropylldene group, cyclo-he2ylidene group, benz:ylidene group or tetrahydro-4-~3 _ pyranylidene group; the 4',6'-carbamate ring once formed is ring-fi~sioned by treatment with an alkali to re-generate the free 4'-hydro~yl group and the free 6'-amino group; and finally the free 6~-amino group is blocked with an alkoxycarbonyl or aralkyloxycarbonyl group or an alkanoyl group such as acetyl. In this way, we have succeeded in preparing a desired, ~uitable protected derivative of kanamycin A, and as a consequence of it, we have now succeeded to provide a route by which semi-synthesis of 3',4'-dideo~ykanamycin A is achieved.
Thus, we have now firstly succeeded in synthetizing the new compound, 3',4.'-dideo~ykanamycin A, and we have also succeeded in synt;hetizing a l-N-(a-hydro~y-~ -amino-alkanoyl)-3',4'-dideo~:ykanamycin A, particularly l-N-(2-hydro~y-3-aminopropionyl)-3',4'-dideo~ykanamycin A and l-N-((S)-2-hydro~y-4-~inobutyryl)-3',4l-dideo~ykanamycin A by condensin~ the l-amino group o 3',4'-dideoxykanamycin A with an iso~eryl greup, particularly DL- or ~- or D-2-hydro~y-3-aminopropion.yl group, or with (S)-2-hydro~y-4-aminobutyryl group. We have further found that the newderivatives of kanamycin A which we have now synthetized are active again~t a wide variety of the re~istant bacteria.
DETAILED DESCRIPTION OF THE INVENTION:
According to a first aspect ~f this invention, therefore~ there are provided as a new compound ~',4'-dideoxykanamycin A and. a l-N-(a-hydro~y-~ -amlnoalkanoyl) derivative of 3',4'-di.deoxykanamycin A represented by ~ ~iza63 _ g _ the general formula:

~H2~H2 ~ 2 4' ~

OH

/ (I) OH

wherein R represents a hydrogen atom or an a-hydro~y-~ -aminoalkanoyl group of the formula -COIH(CH2)nNH2 OH
wherein n is an integer of 1 or 2; and pharmaceutically acceptable acid-addition salts thereof.

The new compound of the general formula (I) according to the fir~t aspect of thi~ invention includes ~',4'-dideoxy-kanamycin A of the for~lula:

~5Z(~63 ~H2NH2 ~H2 Hz OH

(Ia) HO
OH

as well.as l-N-(2-hydro~y-3-aminopropionyl)-3',4'-dideoxy-kanamycin A and l-N-(2--hydroxy-4-aminobutyryl)-3',4'-dideoxykanamycin A represented by a general formula:

r \ /~H-co-clH(cH2)nNH2 OH ~ OH

OH

O (Ib) ~V ., ~0 OH

- . ~

~iZC63 wherein n is an integer of 1 or 2.
Physico-chemical and biological properties of the particular new compouncls according to this invention are de~cribed below.
3',4'-Dideoxykanamycin A is in the form of a color-less powder which does not show any definite melting point.
Its carbonate gave an elemental analysis (C 44.22, H 7.34, N 10.45%) which was substantially coincident with its molecular formula (Cl8H~6N40g 1-1 H2C3) SPeCifiC optical rotation of it was [a]D5 + 116 (c=l, water).
l-~-(DI,2-hydro~y-3-aminopropionyl)-3',4'-dideoxy-kanamycin A is in the form of a colorless powder which does not show a definite melting point. Specific optical rotation [a]25 + 93o (c=l, water).
1-N-((S)-2-hydro~y-4-aminobutyryl)-3~,4'-dideoxy-kanamycin A is also in the form of a colorless powder which does not show any definite melting point. Specific optical rotation ~a]D5 + 91- (c=l, water).
~he minimum inhibitory concentrations (mcg/m~) of the new compounds of this invention against variou~ micro-organisms were determined according to a standard serial dilution method using ]qutrient agar incubation medium at 37-C, the estimation being made after 18 hours incubation.
For comparison purpo~e~ the MIC. of kanamycin A, amikacin and dibekacin was also determined under the same test conditions. The test results so obtained are shown in Table 1 below as the antibacterial spectra of the new compound of this invention.

.. ~ . -~52G63 C) 0 0 0 ~D ~D 0 h ~1l r~
g O ~ ~ o o I I o U~ o ~i ~i o h ~ 4 ,n C\~ O
~rl rl ~ _ ~h ~ d ~ ~ ~oi N !~ h 'd V
~D N~ ~ N~ UN~ ,~

~ O ~ P4 `-- h .Y o o ~i h ~ V
I ~ ~
I rl ... ~ ~ ~
~D 0 ~0 N 0 N N U~ ~O N
r-l ~ O :~1~ t~ 1~ r I t~ ~ ~ ~ 1~ ~1 _~ ~ O C~l P~~ O ~I t~ O t~\ t~ ~1 ~
o ~ h ~;I til E~ O O
~1 ~ ~ C) ~i q ~ O C~
O N _ rl N~C) N lr~ ~J ~J N W
S: C)r~ ~I N ~ ~ ~ U'~ ~ ~ '-C~ .
O O V ~ ~ ~1 ~ ~D
V S~; --` H i ~; I
O
; rd C~ 13 ~ ~ ~ C~
P~ O ~ ~ r-l~I N N N 15~ {\I N N
~ V 5 Or-l a~ ~ O ~ ~ ~ ~D ~ ~ ~ O
~ ~ V ~'; ~ O
E~ o C) C) N1~ `\ N
rl ~ ~11~ N ~ H
I W C) ~ . . . -,~ P. w ~ N ~7 ~ N O ~ O u~
1 ~ ~ o o c~
~OC ~ ~ ~
cd ~d tH rl o ~ ~c ~n o ~ o a~
h ~ ~d C) 0 ~ ~ a) O td ~ ~1 0 rl cd E3 ~ ~) 0 ~1 rl o _ ~ ,~ u~ h ~ H o~
I ~ ~,1 ~ CJ~ O H o b~
~ cd O F4 U~ ~ V q ~
a ~ ~ ~ w ~ ~ ~1 ~I h ~1 ~ ~ ~ oq oa) o o a~
, - h ~ o o cd o c) c~a) ~
o c) c~ w 10 h ~ ^ ~ o O ~~ cd,~ ~ w ~1 C) C~
I O O r~ ~ ~ O C~ O
o o ~ ~ ~ ~ = = ~ ~1 ~ w ~ O ~ ,~ ~ ~
o o ~ :~. h ~: _1~ h h N o ,D r ~ ~ ~ ~ ~ ~ ~
~I E P- ~ I ~ ~ O ~ ~ ~ ~ ~1 ~S
h ~ ~ w 1~ ~ h ~ ~ ~

;3 1~ N Lt~ N
~1 0 0 ~ ~ 0 0 0 0 N O O O O ~C) O O N O O O O r-~ O O O O
rlr~lr~~ r~lr~lr~lr~i A

~D N N Ll~ ~ N 1 Ir~ r~ N N 15~ N r~ N I
........... -1~ t~ N N ~ D ~ ~ r~ r~ O

~D N ~ 1~ N N 1~ P N 0 0 .
1 t~ O N O N
~ r~

1-~ 1~ N L~
N It~ N U~ 15~ 11~ 11~ r--l N 15 .......... -N ~ ~ J N N ~ O -1 0 Il~ N
N 11~
~D O O N O O O N 0 1~ 0 0 N O O
O O ~ 0 0 -~ O O O -1 0 0 r~ r~ r~ r~ r~ r~ r~ r~ r~

N
O O O O ~O O O O O O O O O O O
O O O O o o o o o o o o o I

r-- ~
m ~ ~o p ~ o -~ h O ~ Ha~ ~ I`' h a p: O ~
. C O cd bD ~ h N

h 0 co o _I ~
,D h ~ -~' ~ a) ~
,~ h h h ~ ~

~LlSZ(163 As will be clear from t~e above table, 3',4'-dideo~y-kanamycin A exhibits a remarkably higher antibacterial activity against variou~ re~istant bacteria than the parent kanamycin A, and 1-N-((S)-2-hydroxy-4-aminobutyrY1)-3',4'-dideoxykanamycin A exhibits a higher antibacterial activityagainst the various resistant bacteria than amikacin, i.e.
l-N-((S)-2-hydro~y-4-aminobutyryl)-kanamycin A. This property that the new compounds of this invention show an improvement in the antibacterial activity against the resistant bacteria over the known kanamycin A and amikacin may be expected to be enhanced in future, as amikacin i8 getting a decreased antibacterial activity against the resistant bacteria. According to the new findings of the present inventors obtained in this invention, it may perhaps be ~aid that when an aminoglycosidic antibiotic is modified . .
by sub~ectin~ it to the 3',4'-di-deoxygenation and to the l-N-aminoacylation i~ combination, such modification will give such an amino~lycosidlc antibiotic derivative which e~hibits a hi~her antibacterial activity against the resistant bacteria than such one which m:L~ht be obtained by sub~ecting the amino-glycosidic antibiotic either to the 3',4'-di-deoxygenation or to the l-~-aminoacylation solely.
The acid-addition salt of the new compounds of the general formula (I) according to thi3 invention may be the pharmaceutically acceptable one and includes, for e~ample, a salt thereof with a pharmaceuticælly acceptable inorganic acid such as hydrochloric acid, hydrobromic acid, ~ulfuric ¢~3 -- :16 --acid~ phosphoric acid, nitric acid and the like or with a pharmaceutically acceptable organic acid such as acetic acid, maleic acid, citric acid, agcorbic acid, methanesulfonic acid and t~.e like.
~he 3',4'-dideoxykanamycin A compounds of the general formula (I) according to this invention are usually obtained in the form of the free base t a hydrate or a carbonate thereof from the process of preparing them, but they may be converted into a pharmaceutically acceptable acid-addition salt by reactin~ with a pharmaceutically acceptable in-organic or organic acid as described above.
All of the new compounds of the general formula (I) according to this inve~tion have a low toxicity, as demonstrated by that they all exhibit an ~D50 value of not less than 200 mg/kg upon intravenous injection in mice for estimation of their acute toxicity. Therefore, the new compounds of this invention are useful in therapeutic treatment of infections by various gram-negative and gram-positive bacteria, including the reqistant bacterisl strains.
When estimating the acute toxicity by intravenous in~ection of gentamicin, dibekacin and their l-N-acyl derivative~, some of which are being widely used clinlcally, it has been found that these compounds all have an ~D50 value ranging of 80-120 mg/kg. Accordingly, the low to~icity of the above new compounds of general formula (I~ according to this invention is note-worthy, and the low toxicity of the new compound~ of thi~ invelntion with retaining the antibacterial activity substantially as high as that of the above-de~cribed known drugs will facilitate the clinical use of the new compounds, fulfilling the modern demand for providing efficient and less toxic drugæ.
According to a second aspect of this invention, there is provided a process for the production of the new compound of the formul.a (Ia) shown hereinbefore. Thus, the second aspect of this invention provides a process for the production of ~,4~-dideo~ykanamycin A which comprises the stages of:-(a) treating a protected derivative of kanamycin A
of the formula:

~H2NHB ~HA

4'~0 ~ ~

O (II) ~H2C
~ /
Y

OH

~S~¢~:;3 wherein each A represents an alkylBulfonyl group containing 1 to 4 carbon atom~, an arylsul~onyl group, specially tosyl or an aralkylsulfonyl group, specially benzylsulfonyl aq an amino-protecting group, B represents an alkoxycarbonyl group containing 2 to 5 carbon atoms, an aralkyloxycarbonyl group, specially benzylo~ycarbonyl or an arylo~ycarbonyl group, and Y represents a divalent hydroxyl-protecting group, especially an alkylidene group containing 1 to 6 carbon atoms (preferably isopropylidene), cyclohe~ylidene, benzylidene or tetrahydro-4-pyranylidene group, with a basic reagent such as sodium hydride under anhydrous conditions in an organic solvent to produce a 4',6'-cyclic carbamate derivative of the formula:

o=C~ \
\0~' 0 OH

o (III) ~ `.

OH

wherein A and Y are a~ defined above;
(b) reacting the 4',6'-carbamate compound of the formula (III) with 2,2-dimethoxypropane, l,l-dimethoxy-cyclohe~ane, benzaldehyde7 dimethylacetal or 5,6-dihydro-4-methoxy-2H-pyran under anhydrous conditions in an organic ~olvent in the pre~ence of an acidic catalyst to produce a 2',5-0-protected derivative of the formula:
H~H2C ~EA
=~'0~' ~;

OH20 / (IV) Y/ ~~ / .
\1\~
OH
wherein A and Y are as defined above and X may be the same as or different from Y and represents isopropylidene, cyclohexylidene, benzylidene or tetrahydro-4-pyranylidene group; followed by isolating the 2',5-0-protected der~vative (IV) from the by-produced 2',3'-0-protected derivative;
(c) hydrolizing the 2'95-O-protected compound o~
the formula (IV) ~nder alkaline conditions to fi~sion the 4',6'-carbamate ring ~nd to regenerate the free 4'-hydroxyl ;21~63 ~roup and free 6~-amino group, followed by alkoxycarbonylating, aralkyloxycarbonylating or alkanoylating (egpecially acetylat-ing) the free 6'-amino group of the ring-fission product to give a 3',4'-dihydroxy derivative of the formula:
B'HNH2C ~ A
H0 ~ / ~ o ~ A

o X

O (V) OH
wherein A, Y and X are as defined above and B' represent~
an alkoxycarbonyl group containin~ 2 to 5 carbon atoms, an aralkyloxycarbonyl group, specially benzyloxycarbonyl or an alkanoyl group, specially acetyl;
(d) sulfonylatin~ the 3',4'-dihydroxy compound of the formula (V) by reacting with an alkylsulfonyl or aralkyl-sulfonyl chloride or bromide of the formula:
RlS02C~ (VI) or RlS02Br (VI') or a corresponding sul.fonic acid anhydride of the formula:
(RlS02)2o (VI") .~5~ 63 wherein Rl represents an alkyl group containing 1 to 4 carbon atoms or an aralkyl group, especially benzyl, as the sulfonyl-ating agent under anhydrous conditions in an organic ~olvent to produce a 2",3',4'-tri-0-sulfonyl derivative of the formula:
B'HNH
~--\ ~
RlS02-~ -~J

/ (VIII) OH2~

\o~ 2~
0-02SRl wherein A, B', Rl, X and Y are as defined above;
(e) converting the resulting 2",3'-4',tri-0-sulfonyl-kanamycin A compound into the 3'-eno-kanamycin A compound by treating with zn alkali metzl iodide in the absence of zinc metal powder;
(f) convertin~ the 3'-eno-kanamycin A compound into the 3',4'-dideox~k~namycin A compound by reducing with hydrogen in the presence of a hydrogenation catalyst to saturate the 3',4'-unsaturated bond of the 3'-eno-kanamycin A

2a63 compound;
(g) removing the hydroxyl-protecting groups (X and Y) remaining at -the 5-, 2'-, 4"- and 6"~positions of the kanamycin A compound by acid hydrolysis in a known manner;
(h) removing the amino-protecting group (B') re-maining at the 6'-amino group of the kanamycin A compound in a knowYL manner;
(i) removing the 2"-0-sulfonyl group (-02SRl) remainin~ at the 2"-hydroxyl group and also all the sulfonyl groups (A) remaining aLt the 1-, 3- and 3"-amino groups of the kanamycin A compound b~ treating with an alkali metal or alkaline earth metal in liquid ammonia; and each of the aforesaid stages (g), (h) and (i) being effected in any optional sequence of these stages one after another and at any time after the stage (d) of reacting the 3',4'-.dihydroxy-kanamycin A compound of the formula (V) with the sulfonylating agent (~'I), (VI') or (VI") having been made.
In the process of the second aspect of this invention, therefore, it is possi.ble as an embodiment or a modification thereof to carry out the present process via such a route where (1) the aforesai.d stage (d) is followed, for example, by the under-mentioned. successive stages in the following sequence:-- converting the resulting 2",3',4'-tri-0-sulfonyl-kanamycin A compound of the for~Lula (VII) into the corres-ponting 3'-eno-kanamyc:in A com~ound of the formula:

;3 B'H~I2C ~ A
Y

O _ X
/ (VIII) ~OH2~

0 2"

by ~reating the compound (VII) with an alkali metal iodide in the absence of zinc metal powder;
- removin~ the hydroxyl-protecting groups (X and Y) remaining at the 5-, 2'-, 4"- and 6"-positions of the 3'-eno-kanamycin A compound (VIII) by acid hydrolysis in a known manner;
- converting the 3'-eno-kanamycin A compound 90 partially deprotected into the corresponding 3',4'-dideo~y-kanamycin A compound by reducing with hydrogen in thepresence of a hydrogenation catalyst to saturate the 3',4'-unsaturated bond of the 3'-eno-kanamycin A compound;
- removing the amino-protecting group (B') remaining at the 6'-amino group (B') of the 3',4'-dideoxykanamycin A
compound obtained as the hydrogenation product in the ~ust preceding state; and - removing from the 3',4'-dideox~kanamycin A compound so partially further deprotected the residual 2"-0-~ulfonyl group (-02SRl) remaini:ng at the 2~hydroxyl group and also all the sulfonyl groups (A) remaining at the 1-, 3- and 3"-amino groups of the 3',4'-dideo~ykanamycin A com~ound by treating the latter with an alkali metal or alkaline earth metal in li~uid ammonia, whereby the desired 3',4'-dideoxy-kanamycin A is afforded:
or alternatively (2) the aforesaid ~tage (d) is followed by the under-mentioned subsequent stages in the following order:-- converting the resulting 2",3',4'-tri-0-sulfonyl-kanamycin A compound of the formula (VII) into the corre-sponding 3'-eno-kanamycin A compound of the formula (VIII) by treating the compownd (VII) with an alkali metal iodide in the absence of zinc metal powder;
- converting the 3'-eno-kanamycin A compound (VIII) into the correspondin~ 3',4'-dideoxykanamycin A compound by reducing with hydrogen in the presence of a hydrogenation cataly~t to saturate the 3',4'-unsaturated bond of the 3'-eno-kanamycin A comPo~qd;
- removing the amino-protecting group (B') remaining at the 6'-amino group of the 3',4'-dideoxykanamycin A
compound so obtained in a known manner;
- removing from the ~',4'-dideoxykanamycin A compouuqd so partially deprotected the hydroxyl-protecting groups (X and Y) remainin~ at the 5-, 2'-, 4"- and 6"-position5 of the 3',4'-dideoxykanamycin A compound by acid hydrolysi~
in a known manner; and - removing from the 3',4'-dideoxykanamycin A compound so partially further deprotected the residual 2"-O~sulfonyl group (-02SRl) remainir~ at the 2~-hydroxyl group and al~o all the sulfonyl groups (A) remaining at the 1-, 3- and ~"-amino groups of the 3'~4'-dideoxykanamycin A compound by treating the latter with an alkali metal or alkaline earth metal in liquid ammonia, whereby the desired 3',4'-dideo~y-kanamycin A is afforded:
or further alterna.tively (3) the aforesaid stage (d) is followed by the under--mentioned later stages in the following succession:-- converting the resulting 2",3',4'-tri-0-sulfonyl-kanamycin A compound of the formula (VII) into the corre-sponding 3'-eno-kanamycin A compound of the formula (VIII) by treating the compound (VII) with an alkali metal iodide in the absence of zinc: metal powder;
- removing from the 3'-eno-kanamycin A compound (VIII) the hydroxyl-protecting groups (X and Y) remaining at the

5-, 2'-, 4"- and 6"-positions of the 3'-eno-kanamycin A
compound by acid hydrolysis in a known manner;
- removing from the 3'-eno-kanamycin A compound so partially deprotected the residual amino-protecting group remaining at the 6'-amino group of the 3'-eno-kanamyoin A
compound in a known mcmner;

2~3~3 - removing from the 3'-eno-kanamycin A compound so partially further deprotected the residual 2"-0-sulfonyl group (-02SRl) remaining at the 2"-hydro~yl group and also all the sulfonyl groups (A) remaining at the l-, 3- and 3"-amino groups of the 3'-eno-kanamycin A compound by treating the latter with an alkali metal or alkaline earth metal in liquid ammonia; and - converting the 3'-eno-kanamycin A compound so entirely deprotected i.nto 3',4'-dideoxykanamycin A by reducing with hydroger.L in the pre~ence of a hydrogenation catalyst to saturate t;he 3',4'-unsaturated bond of the 3'-eno-kanamycin A compo~md, whereby the desired 3',4'-dideoxy-kanamycin A is obtained.
In the process of the second aspect invention, the stage (d) of reacting the 3',4'-dihydro~y compound (V) with an alkylsulfonyl or aralkyl~ulfonyl halide (VI) or (VI') or a corre~ponding sulfonic acid anhydride (VI") involves the sulfonylation of 1;he 2"-hydroxyl group of the compound (V), and the stage (e`l of reacting the resulting 2",3'-4'-tri-0-sulfonyl compo~ld (VII) with an alkali metal idodie for the purpo~e of the 3'-enoation must be effected in the ab~ence o. zinc metal powder. If the pre~ence of zinc metal powder would be provided in this ~tage (e), the formation of an aziridine ring between the 3"-amino group and the 2"-sulfonylo~y group should be accompanied, giving an undesired deri~ati~Je. Therefore, it is preferred to protect previously the 2"-hydro~yl ~roup of the 3',4'-dihydroxy compound (V) with an appropriate hydroxyl-protecting group, be~ore the compound (V) i9 reacted with the ~ulfonylation agent of the formula (VI), (VI') or (VI").
The process of the gecond aspect invention may be further modified so that a ~tage of protecting the 2"-hydro~yl g~oup of the compound (V) is interposed therein.
According to a third aspect of thi~ invention, therefore~ there is provided, as a modification of the process of the second aspect invention, a process for the production of 3',4'-d:ideo~ykanamycin A, which comprises the stages of:-(a) treating a protected derivative of kanamycin Aof the formula (II) ~]nown hereinbefore, with a basic reagent such as ~odium hydride under anhydrous condition~ in an organic ~olvent to produce the 4',6'-cyclic carbamate derivative of the formula (III) shown hereinbefore;
(b) reacting the 4',6'-carbamate compound of the formula (III) ~hown hereinbefore, with 2,2-dimethoxypropane, l,l-dimethoxycyclohexLne, benzaldehyde, dimethylacetal or 5 t 6-dihydro-4-methoxy--2H-pyran under anhydrou~ condition~
in an organic solvent in the presence of an acidic cataly~t to produce the 2',5-O~-~rotected derivative of the formula (IV) shown hereinbefoxe, followed by isolating the 2'~5-0-protected derivative (IV) from the b~-produced 2',3'-0-protected derivative (~) protecting the 2"-hydroxyl group of the 2',5-0-protected compound of the formula (IV~ by (1) reacting thi~ 2',5-O~protecte(l compound (IV) with acetyl chloride or acetyl anhydride :Ln pyridine to produce a 3',2"-di-0-acetylated derivative of the formula:
HNH2C ~HA
J
/ O~
\' `' / (IV') /~]~

C) OD
wherein A, X and Y are as defined hereinbefore and each D
repre~ents an acetyl group, (2) subsequently treating the 3',2"-di-0-acetylated derivative (IV') with an ammonlacal alkanol, particularly ammoniacal ethanol to remove pre-ferentially the 2"-acetyl ~roup therefrom and to give the correæponding 3'-mono-0-acetylated derivative, and (3) reacting said 3'-mono-0-acetylated derivative with 3,4-dihydro-2H-pyran under anhydrous conditions in an organic solvent to convert the 2"-hydroxyl group into 2"-tetra-hydropyranylo~y group;
(c') hydrolyzing the resulting 2"-tetrahydropyranyloxy-4',6'-carbamate product under alk~line conditions to remove the 3'-0-acetyl group therefrom and to fission the 4',6'-carbamate ring,giving a 2"-0-protected ring-fission derivative of the formula H2NX2C ~IHA
r \ ~ NHA

HO ~ ~ - ~ /

(IV") Y ~ ~

O--Z

wherein A, X and Y are as defined above and Z represents tetrahydropyranyl group ~ ;
followed by alkoxycar~lonylating, aralkyloxycarbonylating or alkanoylating the free 6'-amino group of the 2"-0-protected ring-fission. prodllct of the formula (IV") to give a 3',4'-dihydroxy-2"-0-protected derivative of the formula:

~i;2~63 -- ~o --B"HNH

~~-- ,1,~;
o ~ x <cH2c ~ o (V' ) o-z wherein X, Y and Z are as defined above and B" represents an alkoxycarbonyl group containing 2 to 5 carbon atoms, an aralkylo~ycarbonyl group, specially benzylo~ycarbonyl or an alkanoyl group, ~pecially acetyl;
(d') sulfonylating the 3',4'-dihydroxy-2"-0-protected derivative of the formula (V') by reacting with an alkylsulfonyl or aralkylsulfonyl chloride or bromide of the afore~aid formula (VI) of (VI') or a sulfonlc acid anhydride of the aforesaid formula (VI") under anhydrous conditions in an organic solvent, particularly in pyridine to produce a 3',4'-di--0-sulfonyl derivative of the formula:

~"HNH2C ~ A
/~\ /~
RlSo2_o ~ O ~ ~/
O --- X
/ (VII') Y ~

O--Z

wherein A, B", Rl, X, Y and Z are as defined above;
(e') converting the resultin~ 3',4'-di-0-sulfonyl-kanamycin A compound into the 3'-eno-kanamycin A compound by treating with an alkali metal iodide in the presence of zinc metal powder or with sodium iodide alone;
(f') converting the 3'-eno-kanamycin A compound into the 3',4'-dideoxykanamycin A compound by reducing with hydrogen in the pre'3e:nce of a hydrogenation catalyst to saturate the 3',4'-un`3aturated bond of the 3'-eno-kanamycin A compound;
(g') removing the hydroxyl-protecting group~ (X, Y
and Z) remaining at the 5-, 2'-, 4"- and 6"- as well as 2"-position~ of the kanamycin A compound by acid hydrolysis;
(h') removing the amino-protecting group (B") ~2~3~3 remaining at the 6'~amino group of the kanmycin A compound in a known manner;
(i') removing all the sulfonyl groupæ (A) remaining at the 1-, 3- and 3"--amino groups of the kanamycin ~ com-pound by treating wit;h an alkali metal or alkaline earth metal in liquid ammonia; and each of the aforesaicL stages (g'), (h') and (i') being effected in any optional sequence of these stages one after another and at any t-lme after the stage (d') of sulfonylating the 3',4'-dihydroxy-kanamycin A compound of the formula (V') with the sulfonylating agent (VI), (VI') or (VI") having been made.
In the proces~3 of the third aspect of thi~ invention, it is also possible as an embodiment or a modification thereof to carry out the present process via such a route where (1) the aforesaid stage (d') is followed, for e~ample, by the under-mentioned successive Qtages in the following sequence:-- removing the hydroxyl-protecting groups (X, Y and Z) remaining at the 5-, 2'-, 4`'- and 6"- as well as 2"-positions of the 3',4'-di-0-sulfonyl-kanamycin A compound of the formula (~II') by acid hydroly~i~ in a known manner;
- con~erting the resulting partially deprotected 3',4'-di-0-sulfonyl-kanamycin A compound (namely, the 6'-~-alkylo~ycarbonyl- or 6'-~-aralkyloxycarbonyl-1,3,3"-tri-N-sulfonyl-3',4'-di-lD-sulfonyl-kanamycin A) into the corresponding 3'-eno-kanamycin A compound by treating ,5~63 with an alkali metal iodide in the presence of zinc metal powder or with sodi~1 iodide alone;
- converting 1,he re~ulting 3' eno-kanamycin A compound into the corresponding 3',4'-dideoxykanamycin A compound by reducing with hydrogen in the presence of a hydrogenation catalyst to saturate the 3',4'-unsaturated bond of the 3'-eno-kanamycin A compound;
- removing the! amino-protecting group (B") remaining at the 6'-amino group of the 3',4'-dideoxykanamycin A compound obtained as the hydrogenation product of the preceding ~tage in a known manner; and - removing fro:m the 3',4'-dideox.ykanamycin A compound so partially further l~eprotected (namely, the 1,3,3"-tri-N-sulfonyl-3',4'-dideox;ykanamycin A) all the suLfonyl groups (A) remaining at the :L-, 3- and 3"-amino groups of the 3',4'-dideo~ykanamycin A compound, whereby the desired 3',4'-dideoxykanamycin A is afforded:
or a'ternatively (2) 1'he aforesaid sta~e (d') is followed by the under-mentionecl subsequent Qtages in the following order:-- converting the resulting 3',4'-di-0-sulfonyl-kanamycin A compound of the formula (VII') into the corre-sponding 3'-eno-kanamycin A compound of the formula:

~S~;63 B"HNH2~ NHA

O -- X
/ (VIII') '~;
O-Z

by treating the compound (VII') with an alkali metal iodide in the presence of zinc metal powder or with sodium iodide alone;
- converting the 3'-eno-kanamycin A compound into the corresPonding 3',4'-dideo~ykanamycin A compound by reducing with hydrogeIl in the pre~ence o~ a hydrogenation catalyst to saturate 1;he 3',4'-unsaturated bond of the 3'-eno-kanamyc~n A compo~md;
- removing from the 3',4'-dideoxykanamycin A compound obtained the residual amino-protecting group (B") remaining at the 6'-amino group of the 3',4'-dideoxykanamycin A
compound in a know~ manner;
- removing from the 3',4'-dideo~ykanamycin A compound 80 partially deprotected the hydroxyl-protecting groups - ~5 -(X, Y and Z~ rem2.ining at the 5-, 2'-, 4"- and 5"- as well as 2"-positlons of the 3',4'-dideo~ykanamycin A compound by acid hydrolysis in a known manner; and - removing from the 3',4'-dideo2ykanamycin A compound ~o partially further deprotected all the sulfonyl groups (A) remaining at the l-, 3- and 3"-amino groups thereof, whereby the desired 3',4'-dideo~ykanamycin A is obtained:
or further alternatively (3) the aforesaid stage (d') ls followed by the under-mentioned stages in the following ~uccession:-- converting t;he resulting 3',4'-di-0-sulfonyl-kanamycin A compound of the formula (VII') into the corre-s~onding 3'-eno-kanamycin A compound of the formula (VIII') by the treatment with an alkali metal iodide in the presence of zinc metal powder or with sodium iodide alone;
- removing from the 3'-eno-kanamycin A compound the residual amino-protec:ting group (B") at the 6'-amino group thereof in a known manner;
- removing from the 3'-eno-kanamycin A compound so partially deprotectecl the hydroxyl-protecting groups (X, Y
and Z) remaining at the 5-, 2'-, 4"- and 6"- a~ well as 2"-positions thereof by acid hydrolysis in a known manner;
- removing from the 3'-eno-kanamycin A compound so partially further deprotected all the sulfonyl groups (A) remaining at the l-, 3- and 3"-amino groups of the 3'-eno-kanamycin A compound by treating the latter with an aIkali metal or alkaline earth metal in liquid ammonia; and ~2(~3 - con~erting t;he 3'-eno-kanamycin A compound so entirely deprotected into 3',4'-dideoxykanamycin A by reducing with hydrogen in the presence of a hydrogenation catalyst to sat~rate the 3',4'-unsaturated bond of the 3'-eno-kanamycin A Compour.L~ whereby the desired 3',4'-dideoxy-kanamycin A is afforded.
~ he process of the second aspect of this invention is now described in detail.
~ irstly, the preparation of the protected derivati~e of kanamycin A of the formula (II) employed as the starting material in this process may be conducted by the following procedure, Kanamycin A is used as the initial material ar.Ld its 6'-amino group is protected by alkoxycarbonylating, arylo~ycarbonylating or aralkyloxycarbonylating this amino group ~electively in a known manner to introduce the amino-protecting alko~ycarbonyl, aryloxycarbonyl or aralkylo~y-carbonyl group (B). As the 6'-amino group is much reactive than the other amino ~sroups of kanamycin A, the amino-protecting group (B) of an alkoxycarbonyl, aryloxycarbonyl or aralkylo~ycarbonyl type may be introduced preferentially into the 6'-amino group, for e~ample, by reacting 1 molar proportion of kanamyci.n A (free ba~e) in water with 0.5 to 3 molar proportion of a chloroformate of the formula:
BCl wherein B represents an alkoxycarbonyl group of 2 to-6 carbon atoms, an arylo~ycarbonyl group such as phenylo~y-carbonyl or an aralkyloxycarbonyl group such as benzyloxy-~ 3 carbonyl, at a temperature of 0 to lO~C according to the method of Kawaguchi et al a~ described in the "Journal of Antibiotics" 25, 695-708 (1972) or U.S. Patent No. 3,781,268, for e~ample~ It is then convenient to prepare, for e~ample~

6'-N-benzyloxycarbonylkanamycin A according to the method of E~ample 1 of U.S. Patent No. 3~925,353. The 6'-N-alkoxycarbonyl-, 6'-N-aryloxycarbonyl- or 6'-N-aralkyloxy-carbonyl-kanamycin A so prepared may be converted into the corresponding 1,3,3"-tri-N-sulfonyl-kanamycin A by alkyl-sulfonylating~, arylsulfonylating~ or aralkyl~ulfonylating~ itin an organic solvent such as aqueous dio~ane.
The preparation of the 1,3,3"-tri-N-sulfonyl-kanamycin A derivative may pref~erably be conducted, e.g., in the following way. The 6'-N-protected kanamycin A is reacted with a substantially ~3toichiometric quantity (i.e. 3 mo~ar proportion or more) of a sulfonic chloride of the formula:
R2 so2c,e wherein R2S02- has the same meaning as that of the aforesaid group A, such as tosy:L chloride in an inert organic solvent such as dio2ane or aqueous dioxane at a temperature o~ 30 to 50C in the pre~ence of an amount of alkali such a~
sodit~t carbonate to give the 6'-N-protected-1,3,3"-tri-N-sulfonyl-kanamycin A. The 1,3,3"-tri-N-sulfonylated kanamycin A so obtained is then reacted with an alkylidenyl-ating agent, an aralkylidenylating agent, a cyclohe~ylidenyl-ating agent such as l,l-dimetho~ycyclohexane or a tetrahydro-~S2C~63 4-pyranylidenylating agent at a temperature of e.g. 10 to 80C to protect the 4"- and 6"-hydroxyl group with a divalent hydro~yl-protecting ~roup (Y) in a known manner as described in U.S. Patent .No. 3,929,762. As the alkylidenylating agent, aralkylidenyl-ating agent, cyclohe~ylidenylating agent and tetrahydro-4-pyranylidenylating agent for this purpose, there may be used such those mentioned in the U.S. Patent No. 3,929,762.
In this way, the 4"- and 6"-hydroxyl groups are protected by being converted into the form of an acetal or a ketal, giving the protected ~erivative of kanamycin A of the aforesaid formula (II) of which the 4"- and 6"-hydro~yl groups have been blocked simultaneously by an alkylidene group, an aralkylidene group, a cyclohexylidene group or a tetrahydro-4-pyranylidene group (Y).
In the process of the second aspect of this invention, the stage (a) thereof is conducted as follows. Thus, the protected kanamycin A derivative of the formula (II) as the starting materisl is d.issolved in an appropriate inert organic solvent such as dimethylformamide and then reacted with a basic reagent, particularly an alkali metal hydride such as sodium hydride similarly to a known method as des-cribed in the "Journal of Antibiotics" Vol. 25, No. 12, 741-742 (1972) or U.S. Patent No. 3,925,354 or 4,125,706 to give the 4',6'-cycllc carbamate compound of the aforesaid formula (III). If the 9tage (a) of forming the 4',6'-cyclic carbamate (III) is omitted in the present process _ ~9 _ and then if the start;ing material (II) is immediately reacted with 2,2-dimethoxypropane, l,l-dimethoxycyclohexane, benzaldehyde or other reagents a~ employed in the stage (b) of the present process, the 2'-hydroxyl group of the kana-mycin A compound cannot be blocked selectively. Accordingly,the pre~ent process is devised to take a course in which the 4',6'-cyclic carbamate is once formed in the stage (a) and then the 2'- and 5-hydro~yl groups are blocked in the stage (b), followed by the :ring-fission of the 4',6'-carbamate ring in the stage (c) to liberate the free 4'-hydroxyl group.
In the stage (b) of the present process, the 4',6'-cyclic carbamate of the formula (III) dissolved in a suitable inert organic ~olvent such as dichloroethane is reacted wibh 2,2-dimethoxypropane, l,l-dimetho~ycyclohexane, benzaldehyde or dimethylacetal or ';,6-dihydro-4-metho~y-2H-pyran under anhydrou~ condition~ i.n the presence of an acidic catalyst ~uch as toluenesulfoni.c acid or sulfuric acid to protect the 5- and 2'-hydroxyl groups of the kanamycin A compound with a divalent hydro~:yl-protecti~g group derived from the acetal- or ketal-forming reagent employed. In this reaction, there are formed the 5,2'-0-protected derivative of the formula (IV) and a corresponding 2',3-0-protected derivative in substantially equal amounts. The former compound (IV) may be separated from the latter by utilizing the dif~erence in their solubility in a proper organic solvent such as chloroform. For this purpose, a chromatographic Reparation is also po~ible.

~52~f~3 In the sta~e (c) of the pre~ent process, the 2',5-0-protected compound of the formula (IV) i8 subjected to hydrolysis under alka.line conditions in an aqueous organic solvent such as aquecus dio~cane containing an amount of an alkali metal carbonate such as sodium carbonate or barium hydroxide to fission the 4~,6~-carbamate ring of the compound (IV). ~he hydrolysis may be effected at a temperature of 20~ to 100-~ (see U.S. Patent Mo. 4,125,706). A~ the conse~uence of the hydrolytic fission of the 4',6'-carbamate ring, the free 4'-hydroxyl group and free 6'-amino group are liberated. Subsequently the free 6'-amino ~roup of the ring-fission product is blocked by alkoxycarbonylation, aralkyloxy-carbonylation or alkanoylation, especially acetylation in a known manner for the pur~ose of second introduction of the amino-protecting group (B'). ~he alkoxycarbonylation or aralkyloxycarbonylation of the 6'-amino group of the ring-fis~ion product in this sta~e may be conducted in a similar way to the alko~cycarbonylation or aralkylo~ycarbonylation of the 6'-amino group which was effected in the procedure of preparing the protect~sd derivative of kanamycin A of the formula (II) as descr:ibed hereinbefore, and using a chloro-formate of the formul~l:
B'Cl wherein Bl represents an alk.o~cycarbonyl or aralkylo~cycarbonyl group which may be the same as or different from the aforesaid amino-protecting alko~cycarbonyl or aralkylo~ycarbonyl OE oup (B). In this stage, howe~er, the 6'-amino group may be ~Z(~63 -- 41 _ protected also by al]~anoylation, preferably by acetylation.
The alkanoylation of the 6~-amino group may be effected in this stage using an alkanoic acid of 2 to 6 carbon atoms, such as acetic acid or an reactive equivalent thereof such as alkanoic acid chloride or anhydride. In this way, the stage tc) of the present process ~ives the 3',4'-dihydro~y derivative of the fo~ula (V) in which the 3'-, 4'- and 2"-hydro~yl groups remain unprotected but all of the other functional hydroxyl and amino groups are protected.
Subsequently to the stage (c) of the process of the second aspect invention, the stage (d) is conducted in which the ~',4'-dihydro~y derivative (V) is alkylsulfonylated or aralkylsulfonylated in an inert organic solvent, preferably in pyridine, by reacting with the sulfonylating agent (VI), (VI') or (VI") to give the 3',4',2"-tri-0-sulfonyl derivative of the formula (VII). The alkylsulfonylating agent of the formula (VI), ~VI') or (VI") may suitably be a lower alkyl-sulfonic halide of 1-4 carbon atoms such as methanesulfonyl chloride or ethanesulEonyl chloride. The aralkylsulfonylating agent of the formula l(VI) to (VI") may suitably be benæyl-8u Lfonic halide. The sulfonylation of the 3'-, 4'- and 2"-hydro~yl groups in th:Ls sta~e may be effected at a tem-perature of -10 to lOt)C and most preferably at ambient temperature and for a reaction time of 30 minutes to 1 day.
In the stage (e) of the present process, the 2",3',4'-tri-0-sulfonyl-kanamycin A compound (VII) obtained in the above stage (d) is di2lsolved in an inert organic solvent :~L3L5Z1~3 and then reacted with an alkali metal iodide such as sodium iodide to be converted into the corresponding 3'-eno-kanamycin A compound. The organic solvent employed may be any inert one, if thi~ can dis~lolve therein both of the tri-0-sulfonyl-ated kanamycin A compound (VII) and the alkali metal iodidesuch as lithium iodide, ~odium iodide and potassium iodide.
Dimethylformamide, dimethylsulfoxide~ acetone, dioxane and the like may be suitable for this solvent. ~he reaction may properly be effected at a reaction temperature of 50 to 150C
and for a reaction time of 10 minutes to 1 day. In most cases, the reaction can be completed in approximately 10 hours. By this reaction, the 3'- and 4'-sulfonyloxy groups are removed with formation of the olefinic double bond between 3'- and 4'-carbon atoms, giving the 3'-eno-kanamycin A compound. In the pre~ent process, the 3'-enoation stage (e) i8 effected by reacting with an alkali metal iodide in the absence of zinc metal powder. In this stage (e), zinc metal powder must not be used. If the 2",3',4'-tri-0-sulfonyl-kanamycin A compound is reacted with an alkali metal iodide in the presence of zinc metal powder, the 2"-sulfonyloxy group o~an react with the 3"-amino group with undesired formation o~ an aziridine ring, giving an un-desirably modified kanamycin A derivative. In contrast, an alkali metal iodide together with zinc metal powder can be employed for the 3l'-enoation if the 3',4'-0-sulfonylated kanamycin A compound has its 2"-hydro~yl group protected by any protective group other than the sulfonyl group, as this ~5~i3 -- 43 _ is observed in the s-tage (e') of the process according to the third aspect of 1this invention~
In the stage l'f) of the present process, the 3'-eno-kanamycin A compound so obtained is converted into the corresponding ~',4'-cLideo2ykanamycin A compound by reducing with hydrogen in the presence of a known hydrogenation catalyst to effect the hydrogenation of the 3',4'-unsaturated bond into the saturat;ed bond. The reduction of the 3',4'-double bond with hydrogen may be effected in a known manner eg. as described in U.S. Patent No. 3,753,973 by passin~ hydro~en gas into a solution of the 3'-eno-kanamycin A compound dissolved in an inert solvent such as water, methanol, ethanol, isopropanol, acetone, dioxane, pyridine, tetrahydrofuran, dimethylform-amide, cyclohe~ane, ethyl acetate or a mixed solvent of twoor more of these liquids in the presence of a known hydro-genation catalyst such as Raney nickel, platinum, platinum oxide, palladium, palladium-on-carbon, cobalt-rhodium complex, copper and iron etc. 'rhe hydrogenation of the 3',4'-double bond may be conducted at a temperature of -40-C to 120-C but preferably at a temperature of from ambient temperature t D 100 C and may readily proceed under a atmospheric pressur~s but even under an elevated pressure of 5 to 100 kg/cm2. The reaction time for the hydrogenation may suitably be 0.5 to 48 hours.
'rhe process of the second aspect invention includes al~o the sta~e (g) of removing the residual hydro~yl-~i2~63 protecting ~roups (X and Y), the stage (h) of removing theresidual amino-protec-ting group (B~) remaining at the 6'-amino group, and the stPge (i) of removing the 2"-0-sulfonyl group and also all the sulfonyl groups (A) remaining at the 1-, 3- and 3"-amino groups of the kanamycin A compound.
The removal of these residual protecting groups may be achieved by a known cleprotecting technique normally employed in the synthesis of ~ides. ~ach of these deprotecting stages (g), (h) and (i) may be performed at an appropriate time after the stage (d) of producing the 3',4'-0-sulfonylated kanamycin A compound (VII) was conducted. The sequence in which each of the deprotecting stages (g), (h) and (i) is performed one after another may be chosen properly and optionally. For instance, the stage (g) of removing the divalent hydroxyl-prctecting groups (X and Y) from the 5-and 2'-hydroxyl ~roup~s as well as from the 4"- and 6"-hydroxyl groups of the kanamycin A com~ound may precede the stage (f) of converting the 3'-eno-kanamycin A compound into the corre~ponding 3',4'-dideoxykanamycin A compound by the catalytic hydrogenation.
However, the step (i) of removing the residual 2"-0-sulfonyl group (-02SRl) and the re~idual amino-protecting sulfonyl groups (A) must not be conducted just after the sul-fonylation stage (d), as it could remove even the 3'- and 4'-0-sulfonyl groups just introduced. The removal of the di-valent hydroxyl-protecting groups (X and Y) in the stage (g) may be performed by hydrolysis under weakly acidic ;Z~3 -- ~5 --conditions in the presence of acetic acid or diluted hydro-chloric acid. The removal of the amino-protecting acyl ~roup (~') from the 6'-amino group in the stage (h) may be effected by.hydrogenolysis or by alkaline hydrolysis, depending on the nature of the amino-protecting group employed. When the ~ino-protecting group (B') is an aralkylo~ycarbonyl group such as benzyloxycarbony', this can be removed by hyd.rogenolysis concurrently to the catalytic hydrogenati.on of the 3',4'-unsaturated bond of the 3'-eno-kanamycin A compound which is effected in the above stage (f). The removal in the stage (i) of the residual amino-protecting sulfonyl group~ (A) and the residual sulfonyl grc,up (-02SRl) remaining at the 2"-hydroxyl group of the kanamyci.n A compound may conveniently be per-formed by treating wi.th an alkali metal, specially metallicsodium or an alkaline! earth metal in liquid ammonia in a way similar to the de!sulfonylation method as described in U.S. Patent No. 4,165l,939. Thus, when the residual amino-protecting sulfonyl group~ (A) and the residual 2"-0-sulfonyl group are to be removed by the treatment with alkali metal or alkaline earth met;al in liquid ammonia, this removal ~tage (i) may be effected by reacting with one or more of the alkali metals sel.ected from lithium,sodium and potassium a~ well as the alkali.ne earth metals selected from calcium, magnesium and barium, in liquid ammonia at a reaction temperature of -80-C to O-C and suitably for a time of 0.5 to 24 hours. The quantity of the alkali or alkaline earth ~2(~3 metal used for this reaction may suitably be 10 to 100 mol.
per mol. of the kanamycin A compound to be deprotected and may also be added at once or in small portions into the reaction mixture. After the reaction of removing the residual 2"-0-sulfony~l group and the residual amino-protecting sulfonyl groups (A) was completed, the reaction mixture may be admixed with an amount of water, an alkanol or ammonium chloride to consume up the remaining excessive quantity of the alkali metal or alkaline earth metal, followed by evaporating off the solvent (the li~uid ammonia)~ dissolving the residual solid product in water and subjecting the resulting solution to a purification step, for e~ample, a chromatographic process for the purification purpose.
As stated hereinbefore, the sequence in which any one f the deprotecting stages (g), (h) and (i) is performed one after another may be chosen properly, and hence it is to be noticed that the process of the second aspect invention may be carried out via an~y of the various routes (1), (2) and (3) mentioned hereinbefore. For instance, it is possible for the present process to be carrled out in ~uch a way that one or all of the deprotectin~ stages precedes or precede the stage of converting the 3'-eno-kanamycin A compound into the 3',4'-dideoxykanamycin A compound by the catalytic hydrogenation of the 3',4'-double bond of said 3'-eno compound, as be different from the se~uence of the above descriptions of each stages of the present process given in the above. Accordingly, it is also pos~ible in the 3~52~6;3 present proce~3s that the ~tage (e) of convertin~ the tri-0-sulfonylated kanamycin A compound into the 3'-eno-kanamycin A com~ound i~ followed immediately by the stage (g) of removing both of the 5,2'-0-protecting group (X) and the 4",6"-0-protecting group (Y), for example.
The process according to the third aspect of this invention is now described.
In the process of the third aspect invention, the stages (a) and (b) thereof are entirely the same as the stages (a) and (b) of the process of the second aspect invention, respective:Ly. Subsequently to these stages (a) and (b), there is interposed the stage (j) of protecting preferentially the 2"--hydro~yl group so as to prevent it from being sulfonylate!d, unlike to the stage (d) of the process of the second aspect invention. ~his stage (~) is comprising the three steps, that is, the step (1) of reacting the 2',5-0-protected kanamycin A compound (IV) with acetyl chloride or anhydride in pyridine for acetylation of both the 2"- and 3'-hydroxyl groups; the step (2) of treating the resulting 3',2"-di-0-acetylated product (IV') with ammonical alkanol of 1-4 carbon atoms for the pre~erential removal of the 2"-0-acetyl group therefrom; and the step (3) of reacting the re~3ulting 3'-mono-0-acetylated product with 3,4-dihydro-2H-pyran to block the 2"-hydro~yl group with a hydro~yl-protec1;ing group, tetrahydropyranyl group which i8 readily removable concurrently to the removal of the divalent hydro~yl-protecting groups (X and Y) having ~;2~63 been introduced into the 5-, 2'-, 4"- and 6"-hydroxyl group of the kanamycin A compound. The abo~e ~tep (l) may be performed by reacting l molar proportion of the 2',5-0-protected kanamycin A derivative (IV) with sub~tantially 2 molar proportions or more of acetyl chloride or acetyl anhydride in pyridine at a temperature of 0C to 50C, followed by recoverir~ the resultin~ 3',2"-di-0-acetylated product (IV'~ from the reaction mixture by distilling off the pyridine therefrom. The above step (2) may be con~
ducted by dissolving the resulting 3',2"-di-0-acetylated product (IV') in an alkanol such as methanol, ethanol or butanol containing 2 to lON of ammonia and allowing the solution at a temperature of -10C to +50~C for a time of lO to 400 minutes. The step (~) may be carried out by dissolving the resulting 3'-mono-0-acetylated product in a dry organic solvent such as dichloromethane, tetrahydro-furane and admixing the resulting solution with l molar or more proportion of 3,4-dihydroxy-2H-pyran at ambient tem-perature in the presence of acidic catalyst such as p-toluenesulfonic acid.
After the 2"-0--protecting ~tage (~) waq conducted, the requlting 2"-0-te1;rahydropyranyl-kanamycin A compound (in the form of the 4',6'-carbamate) is hydrolyzed in the stage (c') of the pre~ent process in the same way as in the stage (c) of the process of the second aspect in~ention, when the ~'-0-acetyl eroup is removed therefrom and ~imultaneously the fi~sion of the 4',6'-cyclic carbamate takes place so that the 3'- and 4'-hydroxyl groups as well as the 6'-amino group are liberated in the free state, giving the 2"-O~protected kanamycin A derivative of the formula (IV"). After this, the 2"-O~protected kanamycin A derivative (IV") i~ reacted with a su~stantially l molar proportion or more of a chloroformate of the formula:
~ "Cl wherein B" is an alkoxycarbonyl or aralkylo~y group same as the group B' as defined above, or of an alkanoic acid or a reactive e~uivalent thereto, such as acetic acid, acetic chloride or acetic anhydride~ in the same way as in the alkoxycarbonylation~ aralkyloxycarbonylation or alkanoylation step of the aforesaid stage (c) of the process of the second aspect :in~ention.
In the present process of the third aspect invention, the above-mentioned stJage (c') is followed by the stage (d') in which the 3',4'-di-~0-sulfonation of the 3',4'-dihydro~y-2"-0-protected kanamyc:in A compound (V') is carried out in the same way as in thel stage (d) of the process of the second as~ect invention, but without involving the sulfonyl-ation of the 2"-hydroxyl group which has been blocked by the tetrahydropyranyl grou.p. In this way, there is prepared the 3',4'-di-0-sulfonyl-kanamycin A compound of the formula (VII').
~hereafter, the 3',4'-d~-0-sulfonyl-kanamycin A
compound so obtained is converted into the corresponding 3'-eno-kanamycin A compound in the stage (e') of the ~:~5~(~63 present proce~s by treating with an alkali metal iodide and zinc metal powder according to the Tipson-Cohen method or with sodium iodide alone in a way similarly to the stage (e) of the process of the first a~pect invention. In this stage (e'), the 2"-hydro~yl group of the kanamycin A compound has been blocked, and hence the reaction of converting the 3',4'-di-0-sulfonyl-kanamycin A compound into the 3'-eno-kanamycin compound can be performed by treating with an alkali metal iodide in the presence of zinc metal powder so that the 3'-enoation can be promoted, when the undesired formation of the aziridine ring between the 2"- and 3"-carbon atoms does not take place.
~urther, the 3'-eno-kanamycin A compound so obtained is converted into the corresponding 3',4'-dideoxykanamycin A
compound in the stage (f') of the present process by reducing with hydrogen in the presence of a known hydrogenation catalyst to effect the hydrogenation of the 3',4'-olefinic bond into the saturated bond, in the same manner as in the stage (f) of the process of the second aspect inventionO
The process of the third aspect invention includes also the stage (g') of removing the residual hydroxyl-protecting groups (X, Y and Z), the stage (h') of removing the residual amino-protecting group (B") remaining at the 6'-amino group, and the stage (i') of removing all the sulfonyl groups (A) remaining at the 1-, 3- and 3"-amino groups of the kanamyci:n A compound. These deprotecting stages (g'), (h') and (i') may be effected in the same ~Z~63 manner as in the deprotecting stages (g), (h) and (i) of the process of the second aspect invention, respectively.
Also in the present process, each of these stages (g'), (h') and (it) may be conducted at an appropriate time 5 after the stage (d'), and the ~equence in which e2ch of these deprotecting stages (g'), (h') and (i') is carried out one after another may be properly chosen properly, like to the process of the second aspect invention.
Accordingly, it is possible also for the present process to be carried out via anyone of the various routes mentioned hereinbefore in respect of the process of the second aspect invention. ~or instance, the present process may be conducted in such a way that the stage (g') of removing the residual divalent hydroxyl-~rotecting groups (X, Y and Z) precedes the stage (e') of converting the 3',4'-di-0-sulfonyl-kanamycin A compound into the 3'-eno-kanamycin A compound.
According to a fourth aspect of this invention, there is further provided a process for the production of l-N-(2-hydro~y-3-aminopropionyl)- or 1-N~(2-hydro~y-4-aminobutyryl)-3',4'-dideo~ykanamycirl A represented by the formula (Ib) shown hereinbefore, which comprises the steps of:-(i) acylatin~ the l-amino ~roup of 3',4'-dideoxy-kanamycin A or a partially protected derivative thereof represented by the formula (Ic):-~;2~363- 52 ~

CH2NHE ~HE

4' ~ 2 OH

/ (Ic) /~'\ /

HO ~ ~
OH

wherein each ~ represents hydrogen atom or an amino-protecting group, preferably an alkoxyo~ycarbonyl containing 2 to 5 carbon atoms, an aral~;ylo~ycarbonyl, ~pecially benzylo~y-carbonyl or an arylo~y~carbonyl group, with an a-hydro~y-~ -aminoalkanoic acid of the formula:
E'H~(CH2)nlH-COOH (IX) OH
wherein _ i8 1 or 2, or an amino-protected derivative thereof or a functional derivative thereof, to produce a l-N-acylated compound of the formula:

(~H2NHE
\ ~ NH-CO-CHO~
2)n OH

(Id) CH:20H

HO
OH

wherein E and n are a~i defined above and B' is hydrogen or an amino-protecting ~ oup; and (ii) removing the amino-protecting group(s) (E and E'), if remaining, from the compound of the formula (Id).
The proce~s of the fourth aspect invention i8 here described in detail.
In thi~ process, it is principally possible to employ 3',4'-dideo~ykanamycin A ~ree base or an acid-addition salt thereo~ as the ~tarting material, withoutblocking previously the amino groups other than the l-amino OE oup of the kanamycin A compound. However, it is preferred to use a partially protected derivative of ~',4'-dideoxy-kanamycin A having some of the amino groups protected other than the l-amino group thereo~ which i~ repre~ented by the ~5~ 3 above formula (Ic). The amino-protecting group available for the partial protection of the amino groups of 3',4'-dideoxykanamycin A may be any of known, conventional amino-protecting groups. Typical examples of amino-protecting groups include alkylo~ycarbonyl such as tert-butoxycarbonyl and tert-amyloxycarbonyl; cycloalkyloxycarbonyl such as cyclohexyloxycarbonyl; aralkyloxycarbonyl such as benæylo~y-carbonyl; acyl such as trifluoroacetyl and o-nitropheno~y-acetyl; phosphinothio;yl such as diphenylphosphinothioyl and dimethylphosphinothioyl; and phosphinyl such as di-phenylphosphinyl. Divalent amino-protecting groups such as phthaloyl may also be used. Protection of amino groups in the form of a Schiff base is also utilizable. The method of introducing these amino-protecting groups into the 3- and/or 6'-amino groups of 3',4'-dideoxykanamycin A
may be performed by any of processes known per se in the synthesis of peptides and other organic compounds, for e~ample those using an acid halide, acid azide, active ester or acid anhydride as an amino-protecting group-introducing reagent, as de~cribed, for e~ample, in U.S. Patent No.
4,107,424. Depending upon the amount of amino-protecting group-introducing rea~ent used which is in the range of 0.5 to 6 molar equivalents, it i8 possible to produce a mixture of different, partially amino-protected derivatives of 3',4'-dideo~ykanamycin A in any proportion due to the difference in reactivity among the respective amino groups of the starting compound. Mi~ture~ of such partially ~52(;~63 amlno-protected derivatives of 3',4'-dideo~ykanamycin A
may al~o be used ln the acylat~on step (i) of the present process. It i.s therefor~ convenient for the a~ylation step (i) to wse a crude product of the a~ino-protecting method which i8 usually a mixture of partiallyam~no-protected deri~ati~e~ of ~',4'-dideo~ykanamycin A
as it ls without purifyin~ it. Thus, in the method of introducin~ the amino-protecting group, the amino-protecting group-intrc,ducing reagent may preferably be used in an amount of l. to 5 molar equivalents in an aqueous organic solven.t.
An alternative method for the introducting of an amino-protecting grouE~ is described in our copending published Japanese Pa1:ent Application No. 138402/78 filed on November ll, 1978, our U.S. Patent No. 4,297,485 filed on November 2, 1979 or U. K. published Patent Application No. 79/38894 which is relating to a "zinc-complex" process for the preparation oi. aminoglycosidic antibiotics having some of the amino groups selectively protected. According to this alternative method, 3',4'-dideoxykanamycin A is first converted into a complex thereof with zinc cation and then acylated into a partially amino-protected derivative.
The above-menti.oned "Zinc complex" process is generally concerned with a process for the production of a selectively acylated N-protected clerivative of an aminoglycosidic anti-biotic having a 3-amir.,oglycosyl or ~ $

.

~ 3 3-alkylaminoglycosyl group linked to the 6-hydroxy group of a deoxystreptamine moiety, the process comprising the steps of:
providing an aminoglycosidic antibiotic-zinc cation complex, reacting the complex with an acylation reagent to produce the N-acylated zinc complex, that is to say, a second complex of zinc cations with the aminoglycosidic antibiotic which has non-complexed amino group~ acylated, and reacting the second complex with a reagent to remove zinc cations therefrom to produce the selectively acylated N-protected derivative of the ami:noglycosidic antibiotic. The amino-glycosidic antibiotic-zinc cation complex may be pro~ided by reacting the aminoglycosidic antibiotic with a zinc salt in an inert organic solvent. According to this "zinc complex" process, from 3',4'-dideoxykanamycin A to be employed as the initial material in the process of the fourth aspect invention may be prepared in a facile and efficient way a parti~lly protected derivative of 3',4'-dideoxykanamycin A, for example, by the following procedure:
Thus, 3',4'-dideoxyka:namycin A is dissolved or suspended in an appropriate organic solvent or aqueous organic solvent, and to the resulting solution or suspension is added a suitable zinc salt in a quantity of at least 1 mol per mol of 3',4'-dideoxykanam:ycin A, Any ordinary organic solvent may be employed for t:his purpose, as far as the zinc complex formed after the addition of the zinc salt is at least partially soluble in it. However, use of a large volume of a polar organic solvent and particularly of greater volume of water should preferably be avoided, because the presence of polar organic solvent and water is likely to reduce the stability of th0 resulting aminoglycoside-zinc cation comple~c formed, so that the subsequent acylation reaction for introduction of the amino-protecting group i9 likely to ~ive unsatisfactory result.
Thus~ it is desirable to use an organic solvent of high solvent power such as dimethylsulfo~cide for the isolvent in which the zinc comole~c is to be formed, but it i~ feasible to employ aqueous dime!thylsulfo~ide, dimethylformamide, aqueous dimethylformamide, a mi~cture of dimethylsulfoxide and dimethylformamide, tetrahydrofuran, aqueous tetrahydro-furan, and even a lower alkanol such as methanol, ethanol and aqoue methanol.
Zinc cation may be supplied in the form of a zinc salt to the reaction system where the zinc comple~c ls formed.
Any zinc salt which i9 formed by reaction of zinc cation with an ordinary inorganic or organic acid may be used for the present purpose. In general, however, it iis desirable to employ a zinc salt of a weak acid, such a~ zinc acetate.
As long as the total molar quantity of zinc salt used is at least equal to the molar quantity of the P~inoglycosidic antibiotic, the comple~cing reaction may proceed. However, it is preferable to use the zinc salt in a quantity of sub-stantially more than 1 mol per mol of the i~minoglycosidic antibiotic, 80 that the equilibrium of the comple~cing ~2~i3 reaction is ~hifted in favor of the formation of the zinc complex. Favorable yield of the zinc complex may be obtained when using the ~inc salt in a quantity of about 2.3-6 mol per mol of the aminog.lyco~ide, but in practice it is most preferable to use the zinc salt in a quantity of 4-5 mol per mol of the aminog:Lycoside. Time required for complete comple~ing reaction after the addition of the zinc salt may vary depending on the nature of the organic solvent used, and it may be in the range of "instantaneously" (when using aqueous organic solvent) to 20 hours. The complexing re-action normally may proceed at ambient temperature, but heating or cooling may be done.
In this way, a solution or suspension containing the zinc complex of the amlinoglycoside is prepared, to which is then added an acylation reagent having an acyl group to be introduced as the amino-protecting group.
The acylation reagent employed for this purpo~e of intro~ucing the amino-protecting ~roups may be a usual amino-protecting reage.nt, and this is used to ensure that the non-complexed 3- and 6'-amino groups in the resultant ~',4'-dideoxykanamycin A-zinc cation comple~ are acylated by and blocked with the acyl group of the acylation reagent.
The acyl group availab:le in this invention may be an alko~ycarbonyl group, ~m aralkylo2ycarbonyl group or an arylo~ycarbonyl group or an arylsulfonyl group which are all the con~entional ~lino-protecting group. The acylation reagent available for l;his purpose may either be a ~5iZI~;3 chloroformate of the following general formula R3-o-Co-C~ (Xa) wherein R3 is hydrogen~ an alkyl group9 particularly an alkyl group of 1-6 ca.rbon atoms, an aryl group, particularly phenyl, or an aralkyl group, especially benzyl, and these groups being occasionally further substituted, or a p~
nitrophenyl carbonate of the following general formula:
R30-co-o-c6Hs-p-No2 or active N-hydroxysuccinimide ester of the following formula: o 3 ~
R 0-C0-0-N ~ (Xc) or an azidoformate of the following formula:
R30-Co-N3 (~d) where R3 is as definecl above; or a sulfonic acid of the following formula:
R4So3H (~e) wherein R4 is an aryl group such as phenyl, either sub-stituted or unsubstituted, or an acid halide, acid an-hydride or active este!r of said sulfonic acid.
Particular examples of the available acylation reagent include p-nitrophenyl formate, p-nitrophenol ester of trifluoroacetic acid, trifluoroacetic acid ester, N-benzyloxycarbonyloxysuccinimide (a representative active ester), N-benzylo~ycarbonylo~yphthalimide, benzyloxy-carbonyl chloride, p-methoxybenzyloxycarbonylo~y-p ~S;2~3 _ 60 --nitrophenyl, t-buto~ycarbonylazide, phenoxycarbonyl chloride, tosyl chloride, mesyl chloride and others.
The acylation reagent, either as such or as a solution in a solvent such as tetrahydrofuran and dimethylsulfoxide or in a mi~ture of these solvents, may be added to the solution or suspensio:n containing the aminoglycoside-zinc complex. The molar ~uantity of the acylation reagent added may usually be equal to or a little exce~sive than the number of the non-complexed ~mino groups with which the acylation reagent is to react. In some cases, however, the molar quantity of the acylation reagent added may be up to a molar quantity of about 3 t:Lme~ higher than the number of the non-complexed amino group~3. The acylation reagent may be added either at once or in portions slowly over a duration of 2-~
15~ hours, though it may usually be added over a time of 30minutes to 1 hour. The acylation may be conducted at a temperature of -20-C to 100C but may normally be effected at a temperature rangi.ng from 0C to ambient temperature.
In some cases, the reaction temperature may be kept low at the time of addition of the acylation reagent and be then elevated gradually as the acylation proceeds. Normally, the acylation reaction. may be effected in situ in the organic solvent in which the aminoglycosidic antibiotic-z~nc cation complex wa.s formed. This acylation of the zinc comple~ produces the N-acylated zinc comple~ (the aforesaid ~econd complex~, that is, the complex of zinc cations with the selectively N-acylated aminoglycosidic ~2¢63 _ 61 --antibiotic derivative.
According to the "zinc complex" process stated above, the step of the acylation of the aminoglycoside-zinc cation complex is followed by the ~tep of removing zinc cation from the second complex, ie. the N-acylated zinc complex (namely, de~troying of the zinc complex) to yield the selectively protected N-acylated derivative of the PminO-glycoside which is free from zinc cations.
~or removal of zinc cation from the second complex ie.
the N-acylated zinc com~lex, it is necessary to treat the N-acylated zinc complex with a suitable reagent which removes zinc cætion from said N-acylated zinc comple~. ~or this purpose, there are many available methods. The fir~t method is to react a zinc-precipitating agent, which i8 capable f converting zinc cation into a water-insoluble zinc com-pound such as zinc sulfide, zinc hydroxide or zinc carbonate while the N-acylated zinc complex is still remaining dis-solved in the acylation reaction mixture where the amino-~lycosidic antibiotic-zinc cation complex has been acylated, or after it is transferred into a new solution in a fresh volume of an organic ~301vent from said acylation reaction mixture.
The zinc-precipitating agent available in the first method include hydrogen sulfide, an alkali metal sulfide such as sodium sulfid~, ammonium sulfide, an alkaline earth metal sulfide such as calcium sulfide and an alkall metal carbonate such as sodium carbonate or ammonium hydroxide.

~ 3 A ~econd method i8 (i) to concentrate or concentrate to dryness by evaporation, of the solvent or (ii) to dilute with a liquid diluent the aforesaid acylation reaction mi~ture or the new solution of the N-acylated zinc complex trans~erred into the fre~h volume of the organic solvent so as to give an oily or solid deposit, concentrate or residue, followed by recovering the desired N-acylated aminoglycosidic antibiotic derivative from said deposit, concentrate or residue in any way. The liquid diluent available in this second method is water or a such an organic liquid in which the N-acylated zinc complex as the whole or the N-acylate!d aminoglycosidic antibiotic derivative moiety of said N-acylated zinc comple~ has no or little solubility.
The second complex of zinc cations with the selectively N-acylated aminoglycosidic antibiotic derivative once separated may be admi~ed with water or a polar organic solvent, either anhydrous or aqueous, which serve~ as the zinc cation-removing reagent. This polar organic solvent is either such one in which the zinc salt is soluble but in which the N-acylated aminoglycosidic antibiotic derivative is insoluble, or such one in which the zinc ~alt i8 iIlBOlUble but in which the N-acylated aminoglycosidic antibiotic derivative is soluble.
The second complex of zinc cations with the N-acylated aminoglycosidic antibiotic derivative once separated may be again dissolved wholly in an organic solvent containing a 21:~63 proportion of water, and the re~ulting ~olution iB SUbJeCted to a chromatoFraphic procedure using a cation-exchange resin, an anion~exchange resin, chelate-exchange resin or a water-insoluble polymer containing functional grou~s capable of combining with a meta'l, which ~erves as the zinc cation-removing reagent.
The acylation :reaction mixture may be directly passed through a colulnn of a cation-exchange resin, an anion-exchange resin, chelate-exchange resin or a water-insoluble polym~r containing the metal-combining functions for adsorption of the second complex of zinc cations with the N-acylated aminoglycosidic antibiotic derivative, and the column i~3 then developed with an aqueous organic ~olvent containing or not containing an amount of acid or base, and the eluate is collected in fractions, followed by recovery of the fractions containing the desired selectively N-acylated aminoglycosidic antibiotic derivative but con-taining no zinc cations.
When the desired N-acylated aminoglycosidic anti-biotic derivative i~3 insoluble or substantially insolublein water, the acylation reaction mixture may be immediately admixed with water, ~o that said derivative is precipitated ~3eparately from the zinc salt remaining dis~olved in water.
In the zinc complex formed in the above-mentioned "zinc complex" proce~3~3, zinc cation~3 are principally com-plexing with l-amino ~nd 3"-amino groups of the amino-glycosidic antibiotic,, and hence the N-acylation o~ the ~21~63 aminoglycosidic antibLotic-~inc cation complex followed by the removal of zinc cations therefrom normally gives the N-acylated aminoglyco~idic antibiotic derivative in which amino group other than l-amino and 3"-amino group~ are protected by the acyl group. When the N-acylated aminoglycosidic antibiotic derivative so obtained from the "zinc comple~" process may then be l-N-acylated with an a-hydro~y-~ -aminoalk~noic acid of the formula (IX) according to the fourth aspect invent~on.
It may be added that the above-mentioned "zinc complex"
process may be applied to the preparation of the protected derivative of kanamycin A o the formula (II) which is to be used as the initial material in the process of the second or third aspect of thi~s invention. Moreover, the partially protected derivative of kanamycin A or 3',4'-dideoxykanamycin A which are to be used as the starting material in the processes of thi~ invention may be prepared also by utilizing the method of Nagabhushan et al as setforth in U.S. Patent No. 4,136,254.
In the first step (i) of the process accordi~g to the fourth aspect of this invention, the l-amino group of 3',4'-dideoxykanamycin A or ~I partially protected derivative thereof is acylated by reacting with an a-hydroxy-~ -amino-alkanoic acid of the formula (IX), particularly 3-amino-2-hydroxypropionic acid (as DI-i30serine, D-i~oserine or L-isoserine) or L-4-amincl-2-hydroxybutyric acid to acylate l-amino group with the 3-amino-2-hydro~ypropionyl or 4-amino-~ 6 3 2-hydroxybutyryl group. This 1 N-acylation may be conducted generally as described eg. in the speci~ication of U.S.
Patent Nos. ~,781,268; 4,001,208 and 4,107,424 or U.E.
Patent No. 1,426,908 according to any known method of synthesis of amides by reacting with an isoserine or I-4-amino-2-hydroxybutyric acid, either in its free acid form or in the form of its reactive equivalent such as an active ester, eg. the dicyclohexylcarbodiimide ester, mi~ed acid anhydride, acid azide in an inert organic ~olvent such as dio~ane, dimethoxyetha~e, dimethylformamide, tetrahydrofuran or aqueous ones of these solvents. Isoserine and L-4-amino-2-hydro~ybutyric acid may be such ones of which amino group has been blocked with en amino-protecting group. Suitable amino-protectin~ group for this purpose may be the same a9 or different from that one which was used for the pre-paration of the partia:Lly protected derivative of 3',4'-dideoxykanamycin A to be l-N-acylated. t-~utoxycarbonyl group i8 a pre~erred amino-protecting group, a~ it is readily removable by treating with a dilute acid such as aqueous trifluoroacetic: acid, aqueous acetic acid and diluted hydrochloric acid. Benzyloxycarbonyl group which is removed by conventional catalytic hydrogenolysis over palladium or platinum oxide catalyst, as well as phthaloyl group which is easily removed by hydrolysis with hydrazine are very convenient as the amino-protecting group to this end.
The acylating reaction in the l-N-acylation step (i) of the process of the fourth a3pect invention may preferably be conducted in an aqueous organic solvent using an active ester of the a-hydrox1r-~ -aminoalkanoic acid (IX). ~he suitable active ester may be N-hydroxysuccinimide ester of isoserine or L-4-benzyloxycarbonylamino-2-hydroxybutyric acid, and this active ester may be employed in a ~uantity of 0.5 to 2 mol., favorably of 1 to 1.5 mol per mol of the 3',4'-kanamycin A to be l-N-acylated. The water-miscible organic solvent for use in the reaction medium may preferably be dio~ane, dimethoxyethane, dimethylformamide, tetrahydro-furan.
Subse~uently to the above step (i), the N-deprotection step (ii) of the present process is carried out to remove all the residual amino-protecting ~roups from the l-N-acylation product (Id) obtained in the above step (i). Theremoval of the residual amino-protecting group may be achieved by a conventional N-deprotecting technique. Such a residual amino-protecting group which is of an alko~ycarbonyl type may be removed by hydrolysis with an aqueous solution of trifluoroacetic acid or acetic acid or with a diluted acid solution such as dilute hydrochloric acid. Such a residual amino-protectin~ group which i8 of an aralkyloxycarbonyl type, for e~ample, benzyloxycarbonyl is readily removed by conventional catalytic hydrogenolysis. When all the residual Pmino-protecting groups are removed from the l-N-acylation product of the step (i) of the present proces~, the desired 1~-N-(2-hydro~y-3-aminopropionyl)- or ~ 3 l-N-(2-hydroxy-4-amin~butyryl)-3',4'-dideoxykanamycin A
of the formula (Ib) iis obtained in a hi~h yield.
The new compo~ds of the formula (I) according to the first aspect invention, and particularly 3',4'-dideoxy-5 kanamycin A, l-N-(2-hydroxy-3-aminopropionyl)-3',4'-dideo~y-kanamycin A and l-N-(]~2-hydro~y-4-aminobutyryl)-3',4'-dideo~ykanamycin A as well as an acid-addition salt thereof are of a very low toxicity and useful as antibacterial agent as stated hereinbefore. The new compounds of this invention and their pharmaceutically acceptable acid-addition salt may be administered orally, intraperitoneally, intra-venously, subcutaneously or intramuscularly using any pharmaceutical form known to the art for such administration and in a similar manner to the known kanamycinq. ~or instance, the new compounds of this invention may be administered orally using any pharmaceutical form known to the art for oral administration. E~amples of the pharma-ceutical forms for oral administration are powders, capsules, tablets, syrup and the like. A suitable dose of the new compounds of this inve;ntion for effective treatment of bacterial infections i,9 in a range of 0.5 to 4 g. per person a day when it given orally. It is preferred that said dose should be orally administered in three to four ali~uots per day. The new compounds of this invention may also be administered by intramuscular iniection at a dosage of 200 to 2000 mg per person two to four times per day. Moreover, the new compound~ of this invention may be -- 6~ --formulated into an ointment for external application which contains the active compound at a concentration of 0.5-5 by weight in mixture with a known ointment base such as polyethylene glycol. ~urthermore, the new compounds of this invention are useful for sterilization of surgical instruments.
According to a fifth as~ect of this invention, therefore, there is provided a pharmaceutical composition comprising a safe and antibacterially effective amount of a new compound of this invention selected from 3',4'-dideo~ykanamycin A; l-N-(2-hydroxy-3-aminopropionyl)-3',4'-dideo~ykanamycin A; l-N-(I-2-hydroxy-4-aminobutyryl)-3',4'-dideo~kanamycin A; and a pharmaceutically acceptable acid-addition salt thereof, as the active ingredient, in com-bination with a pharmareutically acceptable carrier for the active ingredient. In the pharmaceutical composition of this invention, the active ingredient compound may be incorporated in an amolmt of 0.5% to 50% by weight of the whole composition.
According to another as~ect of this invention, there is provided a method for inhibiting bacterial growth which comprises administerin~ an antibacterially effectlve and safe amount of a new compound of this invention according to the aforesaid formu].a (I) to an animal su~ceptible to the bacterial growth. There is further provided a method for inhibiting in ~itro bacterial growth, which comprises contacting a surface susceptible to said bacterial growth, 2~3 with an antibacterially effective amount of a compound of this invention.
In the course of tbR production of 3',4'-dideo~y-kanamycin A according to the process of the second or third invention, there are :formed the various intermediate products which are new and useful for the conversion into 31~4~_ dideo~ykanamycin A in accordance with the processes of this.invention. According to another aspect of this invention, therefore, there is provided as a new inter-mediate a compound of the formula:
B"HNH2(~ NHA
~o\ ~NHA

HO ~ - O
O

/ (Va) ~0~
O--Z ' wherein each A represents an alkyl~ulfonyl group containing 1 to 4 carbon atoms, an arylsulfonyl group, specially tosyl, or an aralkylsulfonyl group, specially benzylsulfonyl group;
B" represents an aIkoxycarbonyl group containing 2 to 5 ~2~63 7o carbon atoms, an aral:kyloxycarbonyl group, specially benzylo~ycarbonyl; or an aryloxycarlbonyl group; X represents isopropylidene, cyclo;he~ylidene, benzylidene or tetrahydro-4-pyranylidene group; Y represents an alkylidene group containing 1 to 6 carlbon atoms, specially isopropylidene, cyclohexylidene, bezy:Lidene or tetrahydro-4-pyranylidene group; and Z' is a hydrogen atom or tetrahydropyranyl group.
The intermediate compound of the formula (Va) includes particularly 6'-N-benzyloxycarbonyl-1,3,3"-tri-N-tosyl-5,2'-0-isopropylidene--4",6"-0-cyclohexylidene-kanamycin A;
and 6'-N-benzyloxycarbonyl-1,3,3"-tri-N-tosyl-5,2'-0-iso-propylidene-4",6"-0-cyclohexylidene-2"-0-tetrahydropyranyl-Xanamycin A.

This invention i5 now de~cribed with reference to Example 1 ~hich i8 illu~trative of the process of the second a~pect invention, to ]3xample 2 and 3 which are illustrative of the process of the third aspect invention, and to Examples 4 and 5 which are illustrative of the proce~s of the ~ourth aspect invention.
Example 1 Synthesis of 3'.41-dideoxykanamYcin A
(1) Preparation of 6''-N-benzyloxycarbonyl-1,3,3"-tri-N-tosylkanamycin A
6'-N-Benzyloxycarbonylkanamycin A (free base) (1.79g) (see the aforesaid "Journal of Antibiotics" Vol. 25, 695-708 (1972)) and anhydrous ~odium carbonate (1.1 g) were di~solved in 50 ml of a mixture of water and dloxane (1:3 by volume), and to the resulting ~olution was added 2.0 g of p-toluene-sulfonyl chloride under stirring. The admixture so obtained continued to be stirred at ambient temperature overnight (for the tri-N-tosylat;ion) and then concentrated to a smaller volume. The concentrated solution was admixed with a volume of water, and the precipitate so deposited was removed by filtration, washed with ethyl ether and dri~d to give the above titled product as a solid. Yield 3.14 g (98%). ~a)25 + 10 (c 0.4, acetone).
Elemental analYsis Found: C 52.10, H 5.56, N 5.12, S 8.68%
Calcd- (for C4 ~ 60N4019S) C 52.21, H 5.59, N 5.18, S 8.90%

~Z~i3 (2) Preparation of 6'-N-benzyloxycarbonyl-4",6"-0-cyclohexylidene-1,3,3"-tri-N-tosylkanamycin A
The sub~tance (1.29 g) obtained in the above pro-cedure (1) was taken up into 4 ml of dimethylformamide, and the resulting solution was admixed with 45 mg of toluene-sulfonic acid and 0.81S m~ of l,l-dimethoxycyclohexane.
The admixture so obtained was allowed to stand at ambient temperature for 6 howrs (for the 4",6"-0-cyclohexylidenation).
The reaction mixture was then poured into a large volume of a solutiQn of sodil~m hydrogen carbonate in water, and the precipitate so deposited was removed by centrifugation, well washed with water and then dried. Yield 1.35 g (98~).
(a)25 ~ 0 (c 0.5, acetone).
Elemental analysis Found: C 54.89, H 6.]0. N 4.63, S 8.52%
. ( r C53H68N40~.9S3) C 54.81, H 5.5l0, N 4.82, S 8.28%
(3) Preparation of 4",6"-0-cyclohexylidene-1,3,3l'-tri-N-tosyl-4'-0:6~-N-carbonyl-kanamycin A

~ii2~3 HNH C NHTs / 21 l r r\lNHTs O ~ OH
~ ~
OH

,OH2C

~ \ ~ / (~5 = tosyl) The substance (~911 mg) obtained in the above procedure (2) was dissolved in 18 m~ of dimethylformamide, and to the resultant solution was added 337 mg of 50X sodium hydride in oil. The a/~mixture was agitated overnight at ambient temperature and then admixed with 3.5 m~ of 4N
acetic acid and further with 50 m~ of toluene. The whole admixture was distill~d to remove the solvents, and the thick syrup so obtainecl was admixed with a large volume of water. The precipitate so deposited wa~ collected by filtration, washed with ethyl ether and dried to give a colorless solid comprising the above titled compound.
Yield 685 mg (85%).
(4) 4",6"-0-cyclohexylidene-4'-0:6'-N-carbonyl-5,2'-0-:

i~opropylidene-1,3,3"-tri-N-tosylkanamycin A

HNH C NHTs O= ~ ~HTs ,OH2C

(\Y}~ (Ts = tosyl) H

The substance (100 mg) obtained in the above procedure (3) was suspended in aL mixture of 4 m~ of dichloromethane and 2.5 m~ of tetrahydLrofuran, and to the resulting suspension was added 2 m~ of 2,2-dimethoxypropane. The admixture 80 obtained. was further ~ixed with 6 m~ of a solution of 0.0~5 N hydrogen chloride in dichloromethane, followed by heating for 17 minutes under reflux (for the 5,2'-0-isopropylidenation). This reaction was conducted in a reactor vessel f.itted with a reflux column at the top of the reactor vessel where a column containing 5 m~
of "Molecular Sieves 5A" (a product of zeolite produced by Union Carbide Co., U.S.A.) was interposed between the bottom of the reflux column and an outlet opening in the top of the reactor vessel in such a way that the vapour distilled from the rea,ction solution pre~ent in the vese~el could arise through a side-armed tube which was connected directly between the reaction vessel and the bottom of the reflux column, so that the condensed vapour containing methanol falling down in the reflux column could then pass via the column of molecular sieves and so that only methanol could be removed by adsorption by the molecular sieves. Thus, the condensed solvent freed from methanol could again come back into the reaction vessel.
If the above reaction solution was heated simply under reflux without removing the methanol vapour by means of said molecular sieve column~ the undesired 2',3'-0-isopropylidene derivative was by-produced in a very higher proportion than the desired 5,2'-0-isopropylidene derivative, so that the latter procluct desired was formed in a very poor yield and could not be recovered in a substantial yield.
The reaction mixture from the above reaction was cooled by ice-cooling and then poured into a large volume of a mixture of dioxane and 1 N aqueous ammonia, and the resulting admixture was concentrated. The concentrated solution so obtained was diluted with a volume of ethyl ether to precipitate a colorless solid. This solid was collected by filtration, washed with water and dried to give 85 mg of a solid. This solid was taken up into 3 m~
of chloroform and the resultant solution was chromatographed ~;2~63 in a column of 5 m~ of silica gel developed with chloroform-ethanol (10:1 by volume) as the eluent ~or a puri~ication purpose. The effluent running out of the silica gel column was concentrated to dryness in vacuo to give 61 mg of a solid. This solid was again taken up into 5 m~ of chloroform, and the solution was heated. As the heating proceeded, the undesired 2~,3~-0-isopropylidene derivative became deposited. The whole solution was allowed to stand at ambient temperature overnight, followed by filtration.
The filtrate so obtained was concentrated to dryness, giving 32 mg of the above titled desired product. (a)2 ~ 20 (c 0.5, acetone).
Elemental analYsis Found: C 53.61, H 5.81, N 4.88, S 8.57%
Calcd- (for C49H64N4l~S3) C 53.83, H 5.90, N 5.13, S 8.80~
(5) Preparation of 6~-N-benzyloxycarbonyl-1,3,3"-tri-N-tosyl-5,2'-0-isopropylidene-4",6n-0-cyclohexylidene-kanamycin A
The substance (4B mg) obtained in the above pro-cedure (4) was dissolve~d in 2 m~ of water-dioxane (1:3 by volume), and the solution so obtained was admixed with 30 mg of anhydrous sodillm carbonate, followed by heating at 50C for 1 hour to effect the hydrolysis of said ~ubstance which brought about the fission of the 4',6'-cyclic carbamate and the removal of the 4',-0:6'-N-carbonyl group. The re~iulting reaction solution was then i~mediately admixed with 80 mg of benzyloxycarbonyl chloride, followed by allowing to stand for 2 hours at ambient temperature (for the 6'-N-benzyloxycarbonylation). The reaction mixture was then neutralized to weakly alkaline by addition of acetic acid, and it was subsequently con-centrated to a smalle:r volume in vacuo. The concentrated solution was admixed l~ith a large volume of water and the solid deposited was removed by filtration, well washed with water and then with e1;hyl ether and dried, affording the above captioned product as a solid. Yield 42 mg (82%).
(~)D5 + 9 (c l, chloroform).
Elemental analysis Found: C 55.75, H 6.07, N 4.48, S 7.82%
Calcd. (for Cs6H72N4l.9S3) C 55.99, H 6.04, N 4.66, S 8.01%
(6) Preparation of 6'-N-benzyloxycarbonyl-l,3,3"-tri-N-tosyl-5,2'-0-isop~ropylidene-4",6"-0-cyclohexylidene-3~,4~,2"-tri-0-benzylsulfonyl-kanamycin A

Bz02CHNH2C NHT s ~~-~
BZO2SO 1 , ~ CH3 ,OH2C

~ s ~ (Ts = tosyl \n ~ Bz = benzyl) S0 Bz 6'-N-Benzyloxycarbonyl-1,3,3"-tri-N-tosyl-5,2'-0-isopropylidene-4",6"-0-cyclohexylidene-kanamycin A (611 mg) obtained in the above procedure (5) was dissolved in 12 m~
of pyridine, and the resulting solution after ice-cooling was admixed with 320 ~ of benzylsulfonyl chloride and then allowed to stand for 2 hour~ under ice-cooling (for the 3',4'-di-0-benzyl~ulfonylation accompanied by 2"-0-benzylsulfonation). The liquid reaction mixture was admixed with 0~2 m~ of water and concentrated to a smaller volume in vacuo. The residual solid was admixed with a volume of water, and the insoluble solid was removed by filtration, washed well with water and dried, giving the above titled product as a solid. Yield 795 mg (94~).
()D5 ~ 70 (c 1, chloroform).

2~J63 I-t~ IV~S
Found: C 55.23, H 5.40, N 3.19 Calcd. (for C77HgoN4~5S6) C 55.58, H 5.45, N 3.37% (7) Preparation of 6'-N-benzyloxycarbonyl-1,3,3"-tri-N-tosyl-5,2'-0-isoplropylidene-4",6" 0-cyclohexylidene-2"-0-benzylsulfonyl-3',4'-dideoxy-3'-eno-kanamycin A

Bz02CHMH2C NHTs ) o ~ NHTs ~ _0~
/

o < ~ ~ s ~ (Ts = tosyl, \ 0 ~ Bz = benzyl) OSO2B~
The 3',4',2"-tri-0-benzylsulfonyl-kanamycin A
derivative (560 mg) obtained in the above procedure (6) was dissolved in 12 ml of dimethylformamide, and the resulting solution was admixed with 6 g of sodium iodide, followed by heating at 100C for 5.5 hours ( for the 3',4'-unsaturation). The reaction m~xture was admixed with a large volume of chloroform, followed by centrifugation.

~15;2~63 The supernatant solution so ob~ained was concentr~ted toa smaller volume and diluted with a volume of water, and the solid deposited was well washed with water and then dried. The solid obtained was taken up i~ 10 m~ of chloroform and then purified by chromatographing on a silica gel column developed with chloroform-methanol(20:1) as the eluent. Concentration of the effluent from the silica gel column to dryness gave the above titled compound as a solid. Yield 218 mg 149~ )D5 + 11 (c 1, chloroform).
Elemental analYsis Found: C 57.11, H 5.66, N 4.09, S 9.43%
Calcd. (for C63H76N4l9S4) C 57.25, H 5.~l0, N 4.24, S 9.70%
(8) Production of 3',4'-dideoxykanamycin A
The 3'-eno-kanamycin A derivative (453 mg) obtained in the above procedure (7) was dissolved in 7 m~ of 80%
a~ueous acetic acid, followed by heating At 80C for 1 hour (for the removal of th~e 5,2'-0-isopropylidene and of the 4",6"-0-cyclohexyliden~e groups). The reaction solution was concentrated to a Ismaller volume and the concentrated solution was admixed w:Lth water to deposit a solid which was subsequently washed with water and then dried. The solid so obtained was comprising the de-isopropylidenated and de-cyclohexylidena1;ed kanamycin A derivative, that is, 6'-N-benzyloxycarbonyl-~1,3,3"-tri-N-tosyl-2"-0-benzyl-sulfonyl-3',4'-dideoxy-3'-eno-k~mamycin A~ 413 mg of thi~ ~olid product was taken up into 4 m~ of dioxane, and the resulting .

solution was shaken under the atmosphere of hydrogen gas at 3 atm., for 2~5 hours at ambient temperature in the pre~ence of 40 mg of platinum oxide added thereto. The reaction solution was filtered to remove the catalyst, and the filtrate wa~ ,concentrated to dryness in vacuo to give 412 mg of a 801i~.
This treatment with hydrogen was to hydrogenate the 3',4'-unsaturated bond with hydrogen into the saturated bond and concurrently to remove the 6'-N-benzyloxycarbonyl group. The solid obtained was identified to comprise 1,3,3"-tri-N-tosyl-2"--0-benzylsulfonyl-3',4'-dideoxykanamycin A. The solid obtaineal was dissolved in about 150 m~ of liquid ammonia ~t -50~C, followed by addition of 400 mg of pieces of metal ~odiuml and by agitation at the same tem-1~ perature as above for 1.5 hours (for the remo~al of theN-tosyl groups and the 2"-0-benzylsulfonyl group).
Thereafter, to the reaction solution in liquid ammonia was added a volume of methlmol, and the admixture was slowly brought to ambient temperature with evaporation of ammonia and subseQuently was subjected to a reduced pressure to expell the residual trace amo~t of ammonia to evaporate off there-from. The solid residue so obtained was dissolved in water and the aqueous solution obtained was neutralized by adding thereto an amount of a strongly acidic cation-exchange resin, Dowex*50W x 2 (H+ form) (a product of Dow Chemical Co., U.S.A.). This resin was removed from the aqueous solution by filtration and then packed into a column, followed by *trademark development with 1 N aqueous ammonia. The eluate was collected in ~ractions, and the fractions containing the sub~tance which was positive to the reaction with ninhydrin were combined ~ogether and concentra~ed to dryness, giving a crude product of 3',4'-dideoxykanamycin A. For purifica-tion, the solid, crude product was dissolved in water and the aqueous solution obtained was charged into a column of CM-Sephadex*C-25 (a product of Pharmacia Fine Co.~ Sweden), followed by gradient development with 0 N. -~ 0.12 N aqueous ammonia. The eluate containing the aimed product was collected and concentrated to dryness in vacuo to give a pure product of 3',4'-ldideoxykanamycin A carbonate as a colorless solid. Yield 115 mg (64%). (a)D5 + 116~ (c 1, water).
Elemental analvsis Found: C 44.22, H 7.3''l, N 10.45 Calcd. (fQr ClgH36N4g l lH2C3) C 43.90, H 7.41, N 10.72%
Example 2 Svnthesls of 3',4'-dideoxvkanamYcin A
(1) Preparation of 3',2"-di-0-acetyl-4",6"-0-cyclohexy-lidene-4'-0:6'-N-c:arbonyl-5,2'-0-isopropylidene-1,3,3'-tri-N-tosyl.kanamycin A

*Trademark ~.

HNH2C NHT~
/ ~ ~ NHTs = ~

CH~
o n Ac ~ 9cetyl) Ac The kanamycin A derivative obtained in the above Example l,the procedurle (4), that is, 4",6l'-0-cyclohexy-lidene-4'-0:6'-N-carbo~nyl-5,2'-0-isopropylidene-1,3,3"-tri-N-tosyl-kanamycin A (210 mg) was dissolved in 4.2 m~
of pyridine, and the resulting solut;ion in pyridine was admixed with 0.11 ml of acetic anhydride, followed by allowing to stand at ambient temperature overnight (for the 3',2"-di-0-acetylat;ion). The reaction solution was concentrated to a ~maller volume and then diluted with water to deposit a precipitate which was subsequently removed by filtration, well wa~hed with water and dried.
There was afforded the above titled product as a colorless solid. Yield 217 mg (96~). (a)25 + 76 (c 0.4, acetone~.
Elemental analvsis Found: C 54.00, H 5.96, N 4.56, S 7.7 Calcd. (for C53H68N4020S3) C 54.07, H 5.82, N 4.76, S 8.17%
N.M.R. spectrum (in deutero-pyridine): ~5.37 (triplet, J=9.5 Hz, H-3'); 5.57 (double triplet, J=9.5 ~ 3 Hz, H-2"); 5.85 (doublet, J=3 Hz, H-l'); 6.65 (doublet, J=3 Hz, H-l").
(2) Preparation of 3'-0-acetyl-4"~6"-0-cyclohexylidene-4'-0:6'-N-carbonyl-5,2'-0-isopropylidene-1,3,3"-tri-N-tosyl-kanamycin A
The kanamycin A derivative (29.6 mg) obtained in the above procedure (1) was dis~olved in 2.5 m~ of a solution of 8 N ammonia in etha~ol, and the resulting solution was allowed to stand for 40 minutes at ambient temperature to effect a partial hydrolysi~ for the removal of the 2"-0-acetyl group. The reaction ~olution was immediately con-centrated to a smaller volume in vacuo, and the re~idual concentrated solution was admixed with a volume of water to depo~it a precipitate which was then removed by filtration, washed with water and clried. The above titled product was obtained as a solid in a yield of 28.5 mg (100~).
N.M.R. spectrum (in deutero-pyridine): ~ 5.40 (triplet, J=10 Hz, ~-3').
(3) Preparation of 6'-N-benzyloxycarbonyl-4",6n-0-cyclo-hexylldene-5,2'-0-i~opropylidene-2"-O~tetrahydropyranyl-~2~3~3 1.3,3"-tri-N-to~yl-kanamycin A

H5C6H2C00CHNH2c o NHT6 ~ / ~NHTs CH3 CH~ ¦

(T~ = to~yl) \

The 3'-0-acetyl-kanamycin A derivative (50.5 mg) obtained in the above procedure (2) was taken up into 0.7 m~
of dichloromethane, and the resulting solution was admixed with 0.86 mg of toluenesulfonic acid and then with 0.1 ml of 3,4-dihydro-2-H-pyran, followed ~y allowing to stand for 3 hours at ambient temperature (for the 2"-0-tetrahydro-pyranylation). The reaction solution was then admixed with 0.02 m~ of trlethylamine and concentrated to dryness, and the residue was dis~olved in a volume of chloroform.

~,5~ 3 The solution 30 obtained was washed with an aqueous solution of sodium hydrogen carbonate and dried over anhydrous sodium sulfate. The solution in chloroform was filtered to remove the sodium sulfate, and the filtrate solution was concentrated to dryness. The residual solid comprising the 2"-0-tetrahydropyranyl product was taken up into 2 m~
of water-dioxane (1:3), and the resulting solution was heated at 50C for 1 hour after 30 mg of anhydrous ~odium carbonate was added th~reto. This treatment brought about the hydrolytic removal of ~he 3'-0-acetyl group and the removal of the 4'-0:6'~-N-carbonyl group,involving in the fission of the 4',6'-cyclic carbamate ring. The reaction solution was subsequenl;ly admixed with 9.0 mg of benzyloxy-carbonyl chloride, followed by allowing to stand for 2 hours at ambient temperature (Yor the 6'-N-benzyloxycarbonylation).
The reaction mixture so obtained was neutralized to weakly alkaline by addition of acetic acid~ and it was then con-centrated to a smaller volume. The concentrated solution was mixed with a large volume of water and the solid so deposited was well washed with water and then with ethyl ether and dried to give 42.3 mg (yield 74%) of the above titled compound as a solid. (a)D5 ~ 28 (c 0.5, chloroform).
Elemental analYsis Found: C 56.65, H 6.27, N 4.17, S 7.25 Calcd. (for C61H80N4020S3) C 56.99, H 6.27~ N 4.36, S 7.48%
(4) Preparation of 6'-N-benzyloxycarbonyl-1,3,3"-tri-N-~ ~7 -tosyl-5,2'-0-isopropylidene-4",6"-O~cyclohexylidene-2t'-0-tetrahydropyranyl-3',4'-di-0-benzylsulfonyl-kanamycin A
The product of the above proced~re (3)~ namely 6'-N-benzyloxycarbonyl-4",6"-0-cyclohexylidene-5~2'-0-isopropylidene-2"-0-tetrahydropyranyl-1,3,3"-tri-N-tosyl-kanamycin A (519 mg) in 10 m~ of pyridine was cooled with ice, and the ice-cooled solution was admixed with 164 mg of benzylsulfonyl chloride. The resulting admixture con-tinued to be ice-cooled for 1 hour for the 3',4'-di-0-benzylsulfonylation. The reaction solution was admixed wLth 0.1 ml of water and then concentrated, and the con-centrated solution was further admixed with a volume of water to deposit a soliLd. This solid was removed by filtra-tion, well washed with water and dried, affording 618 mg (96%) of the above titled compound as a colorless solid.
()25 + 390 (c 1, chloroform).
Elemental analYsis Found: C 56.21, H 5.88, N 3.38, S 9.80%
Calcd. (for C7sHg2N4024Ss) C 5~.52, H 5.82, N 3.52, S 10.06~
(5) Preparation of 6'-N-benzyloxycarbonyl-1,3,3"-tri-N-tosyl-3',4'-dideoxy-3'-eno-kanamycin A
The kanamycin A ~derivative (618 mg) obtained in the above procedure (4) was heated in 10 me of 80~ aqueous acetic acid for 1 hour at 80C to remove the hydroxyl-protecting groups, the :Lsopropylidene group, cyclohexylidene group and tetrahydrop,yranyl group therefrom. The reaction mixture was then concentrated to a smaller volume, followed by addition of water to the resul~ing concentrated solution to deposit a solid. This solid was removed by filtration, washed with water and dried to afford 541 mg (100%) of the de-isopropylidenated, de-cyclohexylidenated and de-tetra-hydropyranylated product, that is, 6'-N-benzyloxycarbonyl-1,3,3"-tri-N-tosyl-3',4'-di-0-benzylsulfonyl-kanamycin A
in the form of a colorless solid. This ~ubstance (339 mg) was taken up into 7 mC of dimethylformamide, and the result-ing solution was admixed with 3.5 g of sodium iodide and 1.8 g of zinc metal powder, followed by heating at 100C
for 1 hour under stirring to effect the reaction for the formation of the 3'-eno-kanamycinA derivative. The reaction mixture was admixed with a large volume of chloroform to deposit the excessive quantity of sodium iodide. The admixture was centrifuged to remove the sodium iodide precipitate, and the organic solvent solution (the super-natant) so obtained was concentrated to dryness in vacuo.
The solid residue was dissolved in 15 m~ of chloroform and the solution was chromatographed for the purification of the kanamycin A derivative by passing through a column of silica gel and developing the column with chloroform-methanol (8:1) as the eluent. The eluate containing the aimed compound, that is,6'-N-benzyloxycarbonyl-1,3,3"-tri-N-tosyl-3',4'-dideoxy-3'-eno-kanamycin A was concentrated to dryness in vacuo to give the above titled product as a l;i63 colorless solid. Yield 203 mg (80~). (a)25 + 15 (c 1, chloroform).
Elemental analysis Found: C 52.92, H 5.48, N 5.18, S 8.87%
Calced. (for C47H58N4l7S3 2 ) C 52.99, H 5.68, N 5.26, S 9.03~
(6) Production of 3',4'-dideoxykanamycin A
The kanamycin A derivative (203 mg) obtained in the above procedure (5) wa's dissolved in 2 m~ of dioxane, followed by the treatment with hydrogen in the same manner as in the above Example 1 (8) in the presence of platinum oxide (20 mg) added to effect the hydrogenation of the 3',4'-olefinic bond ancl the concurrent removal of the 6'-N-benzyloxycarbonyl group. A crude product of 1,3,3"-tri-N-tosyl-3',4'-dideoxyka~namycin A was obtained in a yield o~
204 mg (100~).
This tri-N-tosyl-3',4'-dideoxykanamycin A compound was dissolved in about 100 m~ of liquid ammonia at -50C, to which were then added 300 mg of sodium metal pieces.
The admixture was subjected to the reaction of removing the tri-N-tosyl groups in the same manner as in the above Example 1 (8), followed by the procedure of purification in the same way as in the above Example 1 (8). A purified product of 3',4'-dideoxykanamycin A was obtained in a yield of 67.9 mg (67~)~
Example 3 Svnthesis of 3'.4'-dideoxvkanamycin A

;3 (1) Preparation of 6'-N-benzyloxycarbonyl-1,3,3"-tri-N-tosyl-5,2'-0-isopropylidene-4",6"-0-cyclohexylidene-2"-0-tetrahydrop~anyl-3',4'~-di-0-methanesulfonyl-kanamycin A
The protected kanamycin A derivative obtained in the above Example 2 (3), that is, the 6'-N-benzyloxycarbonyl-4",6"-0-cyclohexylidene-5j2'-0-isopropylidene-2"-0-tetra-hydropyranyl-1,3,3"-tri.-N-tosyl-kanamycin A (640 mg) was taken up into 10 m~ of pyridine, and the resulting solution after ice-cooling was a.dmixed with 135 mg of methanesulfonyl chloride, followed by agitation for 1 hour under ice-cooling to effect the 3',4l-di-0-methanesulfonylation. The reaction mixture, after addition of 0.1 ml of water thereto, was con-centrated to a smaller volume and then diluted with water to deposit a solid which was subsequently removed by filtra-tion, well washed with water and dried. The above titled compound was afforeded as a colorless solid in a yield of 680 mg (95%). ~)25 + 430 (c i, chloroform).
Elemental analvsis Found: C 52.41, H 5.63, N 3.67, S 10.88%
Calcd. ( for C63H84N4024S5) C 52.48, H 5.87, N 3.89, S 11.12%
(2) Preparation of 6'-N-benzyloxycarbonyl-1,3,3"-tri-N-tosyl-3',4'-dideoxy-3'-eno-kanamycin A
The 3',4'-di-0-methanesulfonyl-kanamycin A derivative (563 mg) obtained in the above procedure (2) was heated in 10 m~ of 80% aqueous acetic acid at 80C for 1 hour to remove the hydroxyl-protecting groups, the isopropylidene group, cyclohexylidene group and tetrahydropyranyl group therefrom. The reaction mixture was concentrated to asmaller volume, and the concentrated solution was admixed with a volume of water to deposit a solid. This solid was collected by filtration, washed with water and dried to afford 510 mg of a partially deprotected kanamycin A
derivative, that is, 6'-N-benzyloxycarbonyl-1,3,3"-tri-N-tosyl-3',4'-di-0-methanesulfonyl-kanamycin A. This substance was dissolved in 7 m~ of dimethylformamide, and the resulting solution was admixed with 3.5 g of sodium iodide and 1.8 g of zinc methal powder, followed by heating for 1 hour at 100C to effect the reaction of forming the 3'-eno-kanamycin A derivative. The reaction mixture obtained was admixed with a large volume of chloroform, and the sodium iodide so precipitated was removed from the organic liquid phase by centrifugation. The organic liquid phase was concentrated to dryness in vacuo, and the residual solid was purified by subjecting a solution of it in chloroform to a chromatography on silica gel column developed with chloroform-methano:L (8:1). The above titled compound was afforded as a color:Less solid in a yield of 317 mg (76~).
(a)25 ~ 15 (c 1, chloroform).
Elemental analysis Found: C 52.92~ H 5.48 5 N 5.18, S 8.87 Calcd. (for C47H58N417S3 2 C 52.99, H 5.68, N 5.26, S 9.03%

C~;3 (3) Production o~ 3',4'-dideoxyka~amycin A
The protected 3'-eno-kanamycin A derivative obtalned in the above procedure (2) was sub~ected to the catalytic hydrogenation with hydrogen and also to the treatment with sodium metal in liquid ammonia in the same manner as described in the above Example 2 (6) to give 3',4'-dideoxy-kanamycin A. Yield 101 mg (65~).
Ex mple 4 SYnthesis of l-N-((S)-2-hydroxY-4-aminobutYrYl)-3',4'-dideoxvkanamYcin A
(1) preparation of 3,6''-di-N-benzyloxycarbonyl-3',4'-dideoxykanamycin A
The 3',4'-dideoxykanamycin A carbonate obtained in the Example 1 given herinbefore was dissolved in 8 N aqueous ammonia, and the resulting aqueous solution was concentrated to dryness in vacuo while said solution was prevented from contacting with the carbon dioxide component present in the air. In this way, the free base form of 3',4'-dideoxy-kanamycin A was prepared~ This 3',4'-dideoxykanamycin A
(free base) (85.4 mg) wa~ suspended in 1.3 m~ of dimethyl-sulfoxide, followed by alddition of zinc acetate di-hydrate (Zn(CH3C02)2 2H20) (187 mg) to the resulting suspension.
Into the reaction vessel containing said suspension was introduced a stream of nitrogen gas to replace the air in the reaction vessel by nitrogen gas. The reaction vessel was then sealed and the suspension was agitated at ambient temperature for 3 hours ~mtil the suspension became a homogeneous solution containing the complex of zinc acetate with 3',4'-dideoxykanamycin A so formed. To thls homogenou3 solution was added slowly and in small portions 90 mg of N-benzyloxycarbonyloxy-succinimide in 2 hours. Ethyl ether (5 mQ) was added to the admixture, which was then shaken vigorously and left to stand for a while. The supernatant solution was separated by decantation from the lower syrupy phase which was containing the complex of zinc acetate with the N-ben2yloxycarbonylated 3',4'-dideoxy-kanamycin A. The lower syrupy phase was again admixed with5 m~ of ethylether, shaken vigorously, left to stand and then separated from the supernatant solution. The lower syrupy phase so freshly formed was subjected further 4 times to the treatment with ethyl ether in the same manner as above. A thick syrupy solid (ca. 450 mg) was obtained, which was supposed to be a mixture of 3,6'-di-N-benzyloxy-carbonyl-3',4'-dideoxykanamycin A, its zinc acetate complex, zinc acetate and the solvent u~ed. This thick, syrupy solid was dissolved in 30 m~ of water-dioxane (1:1), followed by a chromatographic separation on a column of CM-Sephadex C-25 developed with water-dioxane (1:1) con-taining 0.1 N ammonia, during which the zinc acetate complex of 3',4'-dideoxykanamycin A as N-benzylo~Jcarbonylated was decomposed to isolate 3,6'-di-N-benzyloxycarbonyl-3',4'-~5 dideoxykanamycin A. The eluate from the CM-Sephadex column containing the substance positive to the ninhydrin reaction was concentrated to dryness in vacuo. The above titled ~521~63 -compound was afforded as a oolorless solid in a yield of 113 mg (83%)- (~)25 + 77 (c 11 water-dimethylformamide = 1:2)~
(2) l-N-acylation of 3,6'-di-N-benzyloxycarbonyl-3',4'-dideoxykanamycin A
The N-protected 3',4l-dideoxykanamycin A derivative (113 mg) obtained in the above procedure (1) was dissolved in 2 m~ of water-dioxane (1:1), and to the resulting solution were added 6.8 mg of anhydrous sodium carbonate and then slowly in 2 hours 59.4 mg of N-hydroxysuccinimide ester (as an active e~ter) of (S)-2-hydroxy-4-benzyloxycarbonyl-amino-butyric acid (C6H5CH20CONHCH2CH2CH(OH)COO-N ~ ) at ambient temperature wlder stirring. The admixture was allowed to stand for 1 hour at ambient temperature, and the reaction mixture so formed was concentrated to dryness in vacuo. The residual ~olid was admixed with a volume of water and the water-insoluble solid matter was separated from the aqueous phase and dried (121 mg).
This water-insoluble solid was mainly comprising l-N-((S)-2-hydroxy-4-N-benzyloxycarbonylaminobutyryl)-3,6'-di-N-benzyloxycarbonyl-3',4'-dideoxykanamycin A formed.
(3) Removal of the amino-protecting benzyloxycarbonyl groups The water-insoluble solid obtained in the above procedure (2) was taken up into a mixture of dioxane(2 m~), water (0.5 m~ and acetic acid (0.05 ml~, and the result~ng solution was shaken und~sr hydrogen gas at 1 atm. for 1 hour at ambient temperature in the presence of 10 mg of palladium-black added thereto to effect the removal of the benzylocy-carbonyl groups by the catalytic hydrogenolysis. The reaction solution was filtered to remove the catalyst, and the filtrate was concentrated to dryness in vacuo.
The residual solid obtained was dissolved in 1 m~ of water, followed by gradient chromatography on a column of CM-Sephadex C-25 developed with water containing 0--~ 0.5 N
ammonia. The eluate from the CM-Sephadex column containing the desired product were concentrated to dryness in vacuo.
The desired l-N-((S)-2-hydroxy-4-aminobutyryl)-3',4'-dideoxykanamycin A was obtained as the mono-carbonate in the form of a colorless solid. Yield 32 mg (33% calculated as the mono-carbonate). ()D5 + 91 (c 1, water).
Exam~le 5 SYnthesis of l-N-(DL-2-hvdroxy-3-aminopropionyl)-3',4'-dideoxykanamYcin A
The N-protected 3~,4'-dideoxykanamycin A obtained in the above Example 4 (1), that is , 3,6~-di-N-benzyloxy-carbonyl-3',4~-dideoxykanamycin A (120 mg) wa~ dissolved in 2 m~ of water-dioxane (1:1), and the resulting solution was admixed with 7 mg of anhydrous sodium carbonate and then with 60 mg of N-hydroxysuccinimide ester of DL-2-hydroxy-3-benzyloxycarbonylaminopropionic acid (C6H5CH20CONHcH2cH(OH)coo_N ~ ) in the same way as in the above Example 4 (2). T:he admixture so obtained was sub-sequently treated entirlely in the same manner as in the Example 4 (2) and further subjected to the cat~lytic hydrogenolysis in the above Example 4 (3). The above titled compound in the form of a mono-carbonate was afforded as a colorless solid in a yield of 42 mg (42%
calculated as the mono-carbonate). ~)25 + 93 (c 1, water).

Claims (11)

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

1. A process for the production of 3', 4' -dideoxykanamycin A according to the formula (I) wherein R represents a hydrogen atom or an a-hydroxy-.omega. -aminoalkanoyl group of the formula where n is an integer of 1 or 2; or a pharmaceutically acceptable acid-addition salt thereof, which comprises the stages of: -(a) treating A protected derivatlve of kanamycin A
of the formula:

(II) wherein each A represents an alkylsulfonyl group containing 1 to 4 carbon atoms, an arylsulfonyl group, or an aralkyl-sulfonyl group, as an amino-protecting group, B represents an alkoxycarbonyl group containing 2 to 5 carbon atoms, an aralkyloxycarbonyl group, or an aryloxycarbonyl group, and Y represents a divalent hydroxyl-protecting group, with a basic reagent under anhydrous conditions in an organic solvent to produce a 4',6'-cyclic carbamate derivative of the formula:

(III) wherein A and Y are as defined above:
(b) reacting the 4',6'-carbamate compound of the formula (III) with 2,2-dimethoxypropane, 1,1-dimethoxy-cyclohexane, benzaldehyde dimethylacetal or 5,6-dihydro-4-methoxy-2H-pyran under anhydrous conditions in an organic solvent in the presence of an acidic catalyst to produce a 2',5-O-protected derivative of the formula:

(IV) wherein A and Y are as defined above and X may be the same as or different from Y and represents isopropylidene, cyclohexylidene, benzylidene or tetrahydro-4-pyranylidene group; followed by isolating the 2',5-O-protected derivative (IV) from the by-produced 2',3'-O-protected derivative;
(c) hydrolizing the 2',5-O-protected compound of the formula (IV) under alkaline conditions to fission the 4',6'-carbamate ring and to regenerate the free 4'-hydroxyl group and free 6'-amino group, followed by alkoxycarbonylat-ing,aralkyloxycarbonylating or alkanoylating the free 6'-amino group of the ring-fission product to give a 3',4'-dihydroxy derivative of the formula:

_ 5 _ (V) wherein A, Y and X are as defined above and B' represents an alkoxycarbonyl group containing 2 to 5 carbon atoms, an aralkyloxycarbonyl group, or an alkanoyl group, (d) sulfonylating the 3',4'-dihydroxy compound of the formula (V) by reacting with an alkylsulfonyl or aralkylsulfonyl chloride or bromide of the formula:
R1SO2Cl (VI) or R1SO2Br (VI') or a corresponding sulfonic acid anhydride of the formula:
(R1SO2)2O (VI") wherein R1 represents an alkyl group containing 1 to 4 carbon atoms or an aralkyl group as the sulfonylating agent under anhydrous conditions in an organic solvent to produce a 2",3',4'-tri-O-sulfonyl derivative of the formula:

(VIII) wherein A, B', R1, X and Y are as defined above;
(e) converting the resulting 2",3',4'-tri-O-sulfonyl-kanamycin A compound into the 3'-eno-kanamycin A
compound by treating with an alkali metal iodide in the absence of zinc metal powder;
(f) converting the 3'-eno-kanamycin A compound into the 3',4'-dideoxykanamycin A compound by reducing with hydrogen in the presence of a hydrogenation catalyst to saturate the 3',4'-unsaturated bond of the 3'-eno-kanamycin A compound;
(g) removing the hydroxyl-protecting groups (X and Y) remaining at the 5-, 2'-, 4"- and 6"-positions of the kanamycin A compound by acid hydrolysis in a known manner;

(h) removing the amino-protecting group (B') remaining at the 6'-amino group of the kanamycin A compound in a known manner;
(i) removing the 2"-O-sulfonyl group (-O2SR1) remaining at the 2"-hydroxyl group and also all the sulfonyl groups (A) remaining at the 1-, 3- and 3"-amino groups of the kanamycin A compound by treating with an alkali metal or alkaline earth metal in liquid ammonia; and each of the aforesaid stages (g), (h) and (i) being effected in any optional sequence of these stages one after another and at any time after the stage (d) of reacting the 3',4'-dihydroxy-kanamycin A compound of the formula (V) with the sulfonylating agent (VI), (VI') or (VI") having been made, and, when R is .alpha.-hydroxy-.omega. -aminoalkanoyl group of the formula where n is an integer of 1 or 2, the steps of:-- 7a -(i) acylating the 1-amino group of 3',4'-dideoxy-kanamycin A or a partially protected derivative thereof represented by the formula (Ic):- (Ic) wherein each E represents hydrogen atom or an amino-pro-tecting group, preferably an alkoxyoxycarbonyl containing 2 to 5 carbon atoms, an aralkyloxycarbonyl, or an aryloxy-carbonyl group, with an a-hydroxy- .omega.-aminoalkanoic acid of the formula:
(IX) wherein n is an integer of 1 or 2, or an amino-protected derivative thereof or a functional derivative thereof, to produce a 1-N-acylated compound of the formula:

- 7b - (Id) wherein E and n are as defined above, and E' is a hydrogen atom or an amino-protecting group, and (ii) removing the amino-protecting group(s) (E and E') if remaining, from the compound of the formula (Id) to give the compound of the formula (Ib).

2. A process according to Claim 1,in which the stage (d) is followed by the under-mentioned stages in the following sequence:-- converting the resulting 2",3',4'-tri-O-sulfonyl-kanamycin A compound of the formula (VIII) into the corresponding 3'-eno-kanamycin A compound of the formula:

(IX) by treating the compound (VIII) with an alkali metal iodide in the absence of zinc metal powder;
- removing the hydroxyl-protecting groups (X and Y) remaining at the 5-, 2'-, 4"- and 6"-positions of the 3'-eno-kanamycin A compound ( IX ) by acid hydrolysis in a known manner;
- converting the 3'-eno-kanamycin A compound so partially deprotected into the corresponding 3',4'-dideoxykanamycin A compound by reducing with hydrogen in the presence of a hydrogenation catalyst to saturate the 3',4'-unsaturated bond of the 3'-eno-kanamycin A compound;
- removing the amino-protecting group (B') remaining at the 6'-amino group (B') of the 3',4'-dideoxykanamycin A

compound obtained as the hydrogenation product in the just preceding Stage; and - removing from the 3',4'-dideoxykanamycin A compound so partially further deprotected the residual 2"-O-sulfonyl group (-O2SR1) remaining at the 2"-hydroxyl group and also all the sulfonyl groups (A) remaining at the 1-, 3- and 3"-amino groups of the 3',4'-dideoxykanamycin A compound by treating the latter with an alkali metal or alkaline earth metal in liquid ammonia, whereby the desired 3',4'-dideoxykanamycin A is afforded.

3. A process according to Claim 1, in which the stage (d) is followed by the under-mentioned stages in the following order:-- converting the resulting 2"-,3',4'-tri-O-sulfonyl-kanamycin A compound of the formula (VII) into the corresponding 3'-eno-kanamycin A compound of the formula (XI) by treating the compound (III) with an alkali metal iodide in the absence of zinc metal powder;
- converting the 3'-eno-kanamycin A compound (VIII) into the corresponding 3',4'-dideoxykanamycin A compound by reducing with hydrogen in the presence of a hydrogenation catalyst to saturate the 3',4'-unsaturated bond of the 3'-eno-kanamycin A compound;
- removing the amino-protecting group (B') remaining at the 6'-amino group of the 3',4'-dideoxykanamycin A
compound so obtained in a known manner;

- removing from the 3',4'-dideoxykanamycin A compound so partially deprotected the hydroxyl-protecting groups (X and Y) remaining at the 5-, 2'-, 4"- and 6"-positions of the 3',4'-dideoxykanamycin A compound by acid hydrolysis in a known manner; and - removing from the 3',4'-dideoxykanamycin A compound so partially further deprotected the residual 2"-O-sulfonyl group (-O2SR1) remaining at the 2"-hydroxyl group and also all the sulfonyl groups (A) remaining at the 1-, 3- and 3"-amino groups of the 3',4'-dideoxykanamycin A compound by treating the latter with an alkali metal or alkaline earth metal in liquid ammonia, whereby the desired 3',4'-dideoxy-kanamycin A is afforded.

4. A process according to Claim 1, in which the stage (d) is followed by the under-mentioned stages in the following succession:-- converting the resulting 2",3',4'-tri-O-sulfonyl-kanamycin A compound of the formula (VIII) into the corre-sponding 3'-eno-kanamycin A compound of the formula (IX) by treating the compound(VIII) with an alkali metal iodide in the absence of zinc metal powder;
- removing from the 3'-eno-kanamycin A compound (IX) the hydroxyl-protecting groups (X and Y) remaining at the 5-, 2'-, 4"- and 6"-positions of the 3'-eno-kanamycin A
compound by acid hydrolysis in a known manner;

- removing from the 3'-eno-kanamycin A compound so partially deprotected the residual amino-protecting group (B') remaining at the 6'-amino group of the 3'-eno-kanamycin A compound in a known manner;
- removing from the 3'-eno-kanamycin A compound so partially further deprotected the residual 2"-O-sulfonyl group (-O-2SR1) remaining at the 2"-hydroxyl group and also all the sulfonyl groups (A) remaining at the 1-, 3-and 3"-amino groups of the 3'-eno-kanamycin A compound by treating the latter with an alkali metal or alkaline earth metal in liquid ammonia; and - converting the 3'-eno-kanamycin A compound so entirely deprotected into 3',4'-dideoxykanamycin A by reducing with hydrogen in the presence of a hydrogenation catalyst to saturate the 3',4'-unsaturated bond of the 3'-eno-kanamycin A
compound, whereby the desired 3',4'-dideoxykanamycin A is obtained.

5. A modification of the process according to Claim 1 for the production of 3',4'-dideoxykanamycin A, which comprises the stages of:-(a) treating a protected derivative of kanamycin A
of the formula (II) shown hereinbefore, with a basic reagent under anhydrous conditions in an organic solvent to produce the 4',6'-cyclic carbamate derivative of the formula (III) shown in claim l;

(b) reacting the 4'6'-carbamate compound of the formula (III) shown hereinbefore, with 2,2-dimethoxypropane, 1,1-dimethoxycyclohexane, benzaldehyde, dimethylacetal or 5,6-dihydro-4-methoxy-2H-pyran under anhydrous conditions in an organic solvent in the presence of an acidic catalyst to produce the 2',5-O-protected derivative of the formula (IV) shown hereinbefore, followed by isolating the 2',5-O-protected derivative (IV) from the by-produced 2',3'-O-protected derivative;
(j) protecting the 2"-hydroxyl group of the 2',5-O-protected compound of the formula (IV) by (1) reacting this 2',5-O-protected compound (IV) with acetyl chloride or acetyl anhydride in pyridine to produce a 3',2"-di-O-acetylated derivative of the formula:

(IV') wherein A, X and Y are as defined hereinbefore and each D
represents an acetyl group, (2) subsequently treating the 3',2"-di-O-acetylated derivative (IV') with an ammoniacal alkanol, to remove preferentially the 2"-acetyl group therefrom and to give the corresponding 3'-mono-O-acetylated derivative, and (3) reacting said 3'-mono-O-acetylated derivative with 3,4-dihydro-2H-pyran under anhydrous conditions in an organic solvent to convert the 2"-hydroxyl group into 2"-tetrahydropyranyloxy group;
(c') hydrolyzing the resulting 2"-tetrahydropyranyloxy-4',6'-carbamate product under alkaline conditions to remove the 3'-O-acetyl group therefrom and to fission the 4',6'-carbamate ring, giving a 2"-O-protected ring-fission derivative of the formula:

(IV") wherein A, X and Y are as defined above and Z represents tetrahydropyranyl group ;

followed by alkoxycarbonylating, aralkyloxycarbonylating or alkanoylating the free 6'-amino group of the 2"-O-protected ring-fission product of the formula (IV") to give a 3',4'-dihydroxy-2"-O-protected derivative of the formula:

(V') wherein X, Y and Z are as defined above and B" represents an alkoxycarbonyl group containing 2 to 5 carbon atoms, an aralkyloxycarbonyl group or an alkanoyl group;
(d') sulfonylating the 3',4'-dihydroxy-2"-O-protected derivative of the formula (V') by reacting with an alkylsulfonyl or aralkylsulfonyl chloride or bromide of the aforesaid formula (VI) or (VI') or a sulfonic acid anhydride of the aforesaid formula (VI") under anhydrous conditions in an organic solvent to produce a 3',4'-di-O-sulfonyl derivative of the formula:

(VII') wherein A, B", R1, X, Y and Z are as defined above;
(e') converting the resulting 3',4'-di-O-sulfonyl-kanamycin A compound into the 3'-eno-kanamycin A compound by treating with an alkali metal iodide in the presence of zinc metal powder or with sodium iodide alone;
(f') converting the 3'-eno-kanamycin A compound into the 3',4'-dideoxykanamycin A compound by reducing with hydrogen in the presence of a hydrogenation catalyst to saturate the 3',4'-unsaturated bond of the 3'-eno-kanamycin A compound;

(g') removing the hydroxyl-protecting groups (X, Y and Z) remaining at the 5-, 2'-, 4"- and 6"- as well as 2"-positions of the kanamycin A compound by acid hydrolysis;
(h') removing the amino-protecting group (B") remaining at the 6'-amino group of the kanamycin A compound in a known manner;
(i') removing all the sulfonyl groups (A) remaining at the 1-, 3- and 3"-amino groups of the kanamycin A
compound by treating with an alkali metal or alkaline earth metal in liquid ammonia; and each of the aforesaid stages (g'), (h') and (i') being effected in any optional sequence of these stages one after another and at any time after the stage (d') of sulfonylating the 3',4'-dihydroxy-kanamycin A compound of the formula (V') with the sulfonylating agent (VI), (VI') or (VI") having been made.

6. The process of Claim 5, in which the stage (d') is followed by the under-mentioned stages in the following sequence:-- removing the hydroxyl-protecting groups (X, Y and Z) remaining at the 5-, 2'-, 4"- and 6"- as well as 2"-positions of the 3',4'-di-O-sulfonyl-kanamycin A compound of the formula (VII') by acid hydrolysis in a known manner;
- converting the resulting partially deprotected 3',4'-di-O-sulfonyl-kanamycin A compound, (namely, the 6'-N-alkyloxycarbonyl- or 6'-N-aralkyloxycarbonyl-1,3,3"-tri-N-sulfonyl-3',4'-di-O-sulfonyl-kanamycin A) into the corresponding 3'-eno-kanamycin A compound by treating with an alkali metal iodide in the presence of zinc metal powder or with sodium iodide alone;
- converting the resulting 3'-eno-kanamycin A compound into the corresponding 3',4'-dideoxykanamycin A compound by reducing with hydrogen in the presence of a hydrogenation catalyst to saturate the 3',4'-unsaturated bond of the 3'-eno-kanamycin A compound;
- removing the amino-protecting group (B") remaining at the 6'-amino group of the 3',4'-dideoxykanamycin A
compound obtained as the hydrogenation product of the preceding stage in a known manner; and - removing from the 3',4'-dideoxykanamycin A compound so partially further deprotected (namely, the 1,3,3"-tri-N-sulfonyl-2"-O-sulfonyl-3',4'-dideoxykanamycin A), all the sulfonyl groups (A) remaining at the 1-, 3- and 3"-amino groups of the 3',4'-dideoxykanamycin A compound, whereby the desired 3',4'-dideoxykanamycin A is afforded.

7. The process of Claim 5, in which the stage (d') is followed by the under-mentioned stages in the following order:
- converting the resulting 3',4'-di-O-sulfonyl-kanamycin A compound of the formula (VII') into the corresponding 3'-eno-kanamycin A compound of the formula:

(VIII') wherein A, X, Y and Z are as defined above, by treating the compound (VII') with an alkali metal iodide in the presence of zinc metal powder or with sodium iodide alone;
- converting the 3'-eno-kanamycin A compound into the corresponding 3',4'-dideoxykanamycin A compound by reducing with hydrogen in the presence of a hydrogenation catalyst to saturate the 3',4'-unsaturated bond of the 3'-eno-kanamycin A compound;
- removing from the 3',4'-dideoxykanamycin A compound obtained the residual amino-protecting group (B") remaining at the 6'-amino group of the 3',4'-dideoxykanamycin A
compound in a known manner;

- removing from the 3',4'-dideoxykanamycin A compound so partially deprotected the hydroxyl-protecting groups (X, Y and Z) remaining at the 5-, 2'-, 4"- and 5"- as well as 2"-positions of the 3',4'-dideoxykanamycin A compound by acid hydrolysis in a known manner; and - removing from the 3',4'-dideoxykanamycin A compound so partially further deprotected all the sulfonyl groups (A) remaining at the 1-, 3- and 3"-amino groups thereof, whereby the desired 3',4'-dideoxykanamycin A is obtained:

8. The process of Claim 5, in which the stage (d') is followed by the under-mentioned stages in the following succession:
- converting the resulting 3',4'-di-O-sulfonyl-kanamycin A compound of the formula (VII') into the corre-sponding 3'-eno-kanamycin A compound of the formula (VIII') by the treatment with an alkali metal iodide in the presence of zinc metal powder or with sodium iodide alone;
- removing from the 3'-eno-kanamycin A compound the residual amino-protecting group (B") at the 6'-amino group thereof in a known manner;
- removing from the 3'-eno-kanamycin A compound so partially deprotected the hydroxyl-protecting groups (X, Y and Z) remaining at the 5-, 2'-, 4"- and 6"- as well as 2"-positions thereof by acid hydrolysis in a known manner;

- removing from the 3'-eno-kanamycin A compound so partially further deprotected all the sulfonyl groups (A) remaining at the 1-, 3- and 3"-amino groups of the 3'-eno-kanamycin A compound by treating the latter with an alkali metal or alkaline earth metal in liquid ammonia; and - converting the 3'-eno-kanamycin A compound so entirely deprotected into 3',4'-dideoxykanamycin A by reducing with hydrogen in the presence of a hydrogenation catalyst to saturate the 3',4'-unsaturated bond of the 3'-eno-kanamycin A compound, whereby the desired 3',4'-dideoxykanamycin A is afforded.

9. A process for the production of 1-N-(2-hydroxy-3-aminopropionyl)-3',4'-dideoxykanamycin A or 1-N-(2-hydroxy-4-aminobutyryl)-3',4'-dideoxykanamycin A represented by the formula (Ib) wherein n is an integer of 1 or 2, which comprises the steps of:-(i) acylating the 1-amino group of 3',4'-dideoxy-kanamycin A or a partially protected derivative thereof represented by the formula (Ic):- (Ic) wherein each E represents hydrogen atom or an amino-pro tecting group, preferably an alkoxyoxycarbonyl containing 2 to 5 carbon atoms, an aralkyloxycarbonyl, or an aryloxy-carbonyl group, with an .alpha.-hydroxy-.omega.-aminoalkanoic acid of the formula:

(IX) wherein n is an integer of 1 or 2, or an amino-protected derivative thereof or a functional derivative thereof, to produce a 1-N-acylated compound of the formula:

(Id) wherein E and n are as defined above, and E' is a hydrogen atom or an amino-protecting group, and (ii) removing the amino-protecting group(s) (E and E') if remaining, from the compound of the formula (Id) to give the compound of the formula (Ib).

10. A compound of the formula (I) wherein R represents a hydrogen atom or an .alpha.-hydroxy-.omega. -aminoalkanoyl group of the formula where n is an integer of 1 or 2; or a pharmaceutically acceptable acid-addition salt thereof, whenever prepared by the process of claim 1 or by an obvious chemical equi-valent thereof,

11. A compound according to Claim 10 which is 1-N-(2-hydroxy-3-aminopropionyl)-3',4'-dideoxykanamycin A or 1-N-(2-hydroxy-4-aminobutyryl)-3',4'-dideoxykanamycin A
represented by the general formula (Ib) wherein n is an integer of 1 or 2, or a pharmaceutically acceptable acid-addition salt thereof, whenever prepared by the process of claim 9 or by an obvious chemical equi-valent thereof.