EP0634895A1

EP0634895A1 - Herbicides

Info

Publication number: EP0634895A1
Application number: EP93906681A
Authority: EP
Inventors: John Edward Duncan Barton; Keith Clinch; Peter John O'hanlon; John Charles Ormrod; Martin John Rice; Michael Drysdale Turnbull
Original assignee: Zeneca Ltd
Current assignee: Syngenta Ltd
Priority date: 1992-04-07
Filing date: 1993-03-16
Publication date: 1995-01-25
Also published as: MA22867A1; UY23567A1; IL105272A0; ZW4393A1; BG97605A; AU3759193A; CN1079965A; WO1993019599A1; TR27245A; CA2132746A1; GB9305238D0

Abstract

A herbicidal composition comprises ester, amide, aryl and heterocyclic derivatives of monic acid A, monic acid B, monic acid C, monic acid ketone and pseudomonic acid. Novel monic acid esters may be represented by the formula (mon)-CO-XR3 wherein (mon) is a residue of a monic acid compound, (mon)-COOH, X is O or S and R3 is an alkyl group substituted by a group -A-R11 wherein A is O or a group S(O)¿x?, and R?11¿ is an optionally substituted alkyl, alkenyl, alkynyl, phenyl, alkyl carbonyl, cycloalkyl or heterocyclyl group.

Description

HERBICIDES

This invention relates to chemical compounds useful as herbicides, to processes for preparing them and to herbicidal compositions and processes utilising them.

A number of derivatives of monic acid are known to have utility as biologically active compounds for use in human and veterinary medicine. Such compounds are described inter alia in GB 1587058.

We have now found that certain monic acid derivatives, including esters, amides and salts have a novel and unexpected herbicidal activity.

According to the present invention there is provided a herbicidal composition comprising a compound of the formula (I) or (IA) or (IB) in admixture with a herbicidally acceptable carrier or diluent, wherein Y

2 3 represents (IC) or (ID) or (IE) and wherein R is a group CO-XR wherein X

3 is 0 or S and R is hydrogen or an agrochemically acceptable ester-forming radical; or R is a group -R wherein R is an optionally substituted aryl or heterocyclic group; or R is a group CO-NR R wherein R and R are the same or different and each represent an agrochemically acceptable amide-forming radical; stereoisomers of the compounds of formula (I), (IA)

2 and (IB) and salts of the compound of formula (I), (IA) and (IB) wherein R

3 3 is COXR , X is 0 and is hydrogen.

According to a further aspect of the present invention there is provided a process of severely damaging or killing unwanted plants, which comprises applying to the plants, or to the growth medium of the plants, a herbicidally effective amount of a compound of the formula (I) or (IA) wherein Y represents (IC) or (ID) or (IE);

2 3 3

R is a group CO-XR wherein X is 0 or S and R rs hydrogen or an agrochemically acceptable ester-forming radical; or

2

R is a group -R wherein R is an optionally substituted heterocyclic

2 group; or R is a group -CO-NH-CI- -CO-W wherein W is hydrogen, optionally substituted phenyl, optionally substituted C- to C₂₀ alkyl, optionally substituted C₂ to C„ alkenyl, optionally substituted C₂ to C_g alkynyl, optionally substituted heterocyclyl or C- to C₇ cycloalkyl; or

2 R is a group -CO-NH-NH- or -C0-NH-NH-C0-Y wherein Y is optionally substituted C. to C_2Q alkyl, optionally substituted C₂ to C„ alkenyl, optionally substituted aryl, optionally substituted aralkyl or optionally substituted heterocyclyl; or

2 5' 6' 5' 6'

R is a group CO-NR R wherein R and R are the same or different and each represent (a) hydrogen, or (b) C-__2Q alkyl, C_{2 g} alkenyl, either of which may be optionally substituted with C« ₇ cycloalkyl, halogen, carboxy, C, ₆ alkoxycarbonyl, carbamyl, aryl, heterocyclyl, hydroxy, C- , alkanoyloxy, amino, mono- or di-(C. ,)alkylamino; or (c) C, ₇ cycloalkyl optionally substituted with C- ₆ alkyl; or

(d) optionally substituted aryl; or

(e) optionally substituted heterocyclyl; or

5' 6'

(f) R and R together with the nitrogen atom to which they are attached represent an optionally substituted C_{R 7} heterocyclic ring; or

2 7 7

R is a group -CO-0-R wherein R is a C-_₂₀ alkyl, C „ cycloalkyl, C, _2Q alkenyl, aralkyl, cycloalkylalkyl, heterocyclyl or heterocyclylalkyl group which group is substituted with a ketonic oxo group; or R is a group

13 13 -CH₂-C0R wherein R is acyl, aralkyl, amino, ureido or carbamic acid ester residue, and stereoisomers of the compound of formula (I) and salts of the compound

3 of formula (I) wherein X is 0 and R is hydrogen.

The term "aryl" as used herein includes phenyl, and naphthyl optionally substituted with up to five substituents which may be independently selected from halogen, C-_₆alkyl, C. ,alkoxy, C- gthioalkyl, halo(C._₆)alkyl, hydroxy(C._₆)alkyl, halo(C,_₆)alkoxy, C₂__g alkenyl, C₂_„ alkeneoxy, C_{2 g} thioalkenyl, C₂__g alkynyl, C₂__g alkyneoxy, C₂__g thioalkynyl, hydroxy, cyano, nitro, amino, mono- and di- C- ₆ alkylamino, C. ₆ alkanesulphinyl, C- _g alkane sulphonyl, carboxy, C- galkoxycarbonyl, eind C. ₆alkoxycarbonyl(C- )alkyl groups.

The term "aralkyl" as used herein includes groups in which the aryl moiety is a phenyl group which may be optionally substituted as hereinbefore defined for aryl and in which the alkylene radical has from 1 to 4 carbon atoms.

The term "heterocyclyl" as used herein includes aliphatic or aromatic single or fused rings comprising up to four hetero atoms in the ring selected from oxygen, nitrogen and sulphur and optionally substituted with aryl, with another heterocyclic ring or with one or more of those substituents mentioned above as optional substituents for aryl.

2 3

When is a group CO-XR , X is preferably 0.

3 Suitable ester-forming radicals, R , include optionally substituted C- to C_2Q alkyl, optionally substituted C₂ to C_2Q, for example C₂ to C_g alkenyl, optionally substituted C₂ to C_2Q, for example C₂ to C_g alkynyl, optionally substituted C, to C₇ cycloalkyl, optionally substituted aryl or optionally substituted heterocyclyl.

Optional substituents which may be present in optionally substituted

3 alkyl, alkenyl or alkynyl groups, such as those represented by R , include

C^_₇ cycloalkyl, C₁_._Q alkoxy, C₁__1Q thioalkyl, C₂__g alkenoxy, C₂_„ thioalkenyl, C₂__g alkyneoxy, C₂__g thioalkynyl, halogen, halo-C._₁₀ alkoxy, halo-C₂__galkeneoxy, halo-C₂_ alkynoxy, carboxy, C- _βalkoxycarbonyl, carbamoyl, aryl, heterocyclyl, hydroxy, cyano, nitro, C- galkanoyloxy, amino, mono- and di-(C. ₆)alkylamino.

Optional substituents which may be present in C- ₇cycloalkyl groups,

3 such as those represented by R , include C. _βalkyl halo-C. ₆alkyl and those substituents listed above in relation to alkyl, alkenyl and alkynyl groups. 3 When R is alkyl, optionally substituted by aryl it may be regarded as an aralkyl group as defined above.

3 Suitable ester-forming radicals R also include C. to C,₀ alkyl optionally substituted by hydroxy, halogen, cyano. Suitable ester-forming

3 radicals R also include C₂ to C-₀, for example C₂ to C, alkenyl, for example vinyl, prop-2-ene-l-yl, and but-l-ene-4-yl which may be unsubstituted or optionally substituted by hydroxy (except in the case of vinyl), by halogen or by cyano.

3 A further preferred group R is a C. .« alkyl group, and preferably a

11 C. . alkyl group, substituted by a group -A-R wherein A is 0 or a group

11 S(0) wherein x is 0, 1 or 2 and R is an optionally substituted C. to

C-_Q, and preferably optionally substituted C. ₆, for example C. to C, alkyl group, an optionally substituted C₂ to C_g, and preferably optionally substitued C„ , , for example C₂ to C, alkenyl group, an optionally substitued C~ to C_g, and preferably optionally substitued C„ ,, for example

C₂ to C, alkynyl group or an optionally substituted phenyl group, an optionally substituted C- g alkyl carbonyl group or an optionally substituted C~_₇ cycloalkyl group, for example an optionally substituted

C, g cycloalkyl group, or an optionally substitututed C- ₇ heterocyclic group, for example an optionally substituted aliphatic heterocyclic group, for example an optionally substituted oxygen-containing aliphatic

3 heterocyclic group. An example of a group R having this substitution is

12 12 the group -(CH.,) ,-A-CBbCH-R wherein n' is an integer from 1 to 4 and R is hydrogen or a C^ to C, alkyl group. A is preferably oxygen.

Optional substituents may be those indicated above for alkyl, alkenyl, alkynyl and aryl respectively. Unless otherwise specified, alkyl, alkenyl and alkynyl groups,

3 incluαddiinngg ffoorr example those present in R , may be straight or branched chain groups.

2 Salts of the compound of formula (I) (IA) and (IB) wherein R is the

3 3 group CO-XR and in which X is 0 and R is hydrogen include for example metal salts, e.g. aluminium, alkali metal salts, such as sodium or potassium, alkaline earth metal salts, such as calcium or magnesium, and ammonium or substituted ammonium salts for example those with lower alkyl-amino such as triethylamine, hydroxy-lower alkylamines such as

2-hydroxyethylamine, bis(2-hydroxyethyl)-amine, or tri-(2-hydroxyethyl)-amine, cycloalkylamines such as bicyclohexyl-amine, or with procaine, dibenzylamine, N,N-dibenzyl-ethylenediamine,

N-ethylpiperidine, N-benzyl-β-phenethyl-amine, dehydroabietylamine,

N,N'-bis-dehydroabietylethylenediamine, or bases of the pyridine type (such as pyridine, collidine, or quinoline) or trimethylsulphonium.

2 4

When R is an optionally substituted heterocyclic group -R , preferred

4 14 15 heterocyclic groups R include groups of formula (II) wherein R and R , which may be the same or different, are independently selected from hydrogen, optionally substituted phenyl, optionally^"Substituted C- to C_2Q alkyl, optionally substituted C₂ to C_g alkenyl, optionally substituted C₂ to C_g alkynyl, optionally substituted heterocyclyl or C- to C₇ cycloalkyl or from those general substituents for heterocyclyl listed above, X is a divalent group, -Y'-C=C- and Y' is oxygen or sulphur. A Preferably R is an optionally substituted heterocyclic ring of

14 15 formula (III) wherein Y is 0 or S and R and R have the meanings given previously. An especially preferred group R is an optionally substituted

14 oxazol-2-yl group, for example a group of formula (IV) wherein R has the meaning given previously.

4 14

Alternatively R may be a group of formula (IV) wherein R is itself an optionally substituted heterocyclic group, for example a group of the formula (IVa), (IVb) or (IVc) in which formulae R¹⁶, R¹⁷, and R¹⁸ may be the same or different each is selected from hydrogen, halogen, optionally substituted (C- g)alkyl, aryl, aralkyl, heterocyclyl, (C» g)alkoxy, hydroxy, carboxy and salts thereof, (C«_g)alkoxycarbonyl, carbamoyl, mono- or di-(C₁_g)alkylcarbamoyl, sulphamoyl, mono- and di-(C- g)alkylsulphamoyl, cyano, nitro, amino, mono-and di-(C.,_g)alkylamino, acylamino, ureido,

(C- g)-alkoxycarbonylamino, (C-_g)alkoxyimino,

2,2,2-trichloroethoxycarbonylamino, acyl, (C- g)alkylthio, arylthio, (C_j-g)alkanesulphinyl, arysulphinyl, (C, g)alkanesulphonyl and arylsulphony1.

Suitably, is a group of formula (IVc) and R , R and R are preferably hydrogen.

3 7 7

A further suitable ester-forming radical R is a group R wherein R represents an optionally substituted C,__2Q alkyl, for example C, ._Q alkyl,

C, _g cycloalkyl, C, _2Q alkenyl, aralkyl, cycloalkylalkyl, heterocyclyl or heterocyclylalkyl group which group is additionally substituted with a ketonic oxo group.

2 7

Thus one sub class of the group R when it is a group -CO-OR is a group of formula (V) wherein Z is an optionally substituted C. to C.₂ alkylene group (-(CH₂) , ,- wherein n" is from 1 to 12) and R represents a

^Cl-10 ^alkv1' ^c3_8 cycloalkyl, C₂__1Q alkenyl, C₂__1Q alkynyl, aryl, aralkyl, cycloalkylalkyl or heterocyclyl group, each of which may be optionally substituted. Optional substituents may be those specified above for the groups alkyl, cycloalkyl, alkenyl, aryl and heterocyclyl respectively.

2 7 7

A further sub-class of the group R is a group CO-OR and R is a

13 13 group -CH₂-C0-R wherein R is suitably a carbamic acid ester residue.

By the term "carbamic acid ester residue" is meant a group of general

19 2021 19 formula -N(R )-C0-NR R wherein R is hydrogen or an optionally

20 21 substitued C. , alkyl group and R and R are independently selected from

5 6 hydrogen or any of the groups R and R given below.

As examples of suitable agrochemically acceptable amide-forming

5 6 radicals R and R , which may be the same or different, there may be mentioned:

(a) hydrogen or

(b) an optionally substituted C, ₂₀ alkyl group, an optionally substituted C₂ 2_Q, for example C_{2 g} alkenyl group or an optionally substituted C₂_2_Q, for example C₂__g alkynyl group or

(c) optionally substituted C, to C₇ cycloalkyl or

(d) optionally substituted aryl or

(e) optionally substituted heterocyclyl; or

(f) R and R together with the nitrogen atom to which they are attached represent an optionally substituted C-_₇ heterocyclic ring or

5 6 22 23 24 22

(g) R is hydrogen and R is a group -NR -N R wherein R is

23 24 hydrogen or C- , alkyl are R and R , which may be the same or different, may independently take any of the meanings given for R and R under (a), (b), (c), (d), (e) and (f) above or (h) R⁶ is a group -NR²²-N=CR²³R²⁴ wherein R²², R²³ and R²⁴ have the meanings given previously or

(i) RR⁵ iiss hhyyddrrooggeenn aanndd RR⁶ iiss aa ggrroouupp -CR²⁵R²⁶-C0-W or - NR²⁷-C0-W wherein W is optionally subjssttiittuutteedd pphheennyyll or optionally ssuubbssttiittuutteedd hheetteerrooccyyccllyyll,, RR ,, RR aanndd RR aarree iinnddeerndently hydrogen or optionally substitued C- g alkyl groups.

5 6 Preferred agrochemically acceptable amide-forming groups R and R are those wherein R is hydrogen or a C, , alkyl group and R is a C. , alkyl group, each of which alkyl groups may independently be optionally substituted by C-_₇ cycloalkyl, C- , alkoxy, halogen, carboxy, C. g alkoxycarbonyl, carbamyl, optionally substituted aryl, optionally substituted heterocyclyl, hydroxy, C. _fi alkanoyloxy, amino, mono- or

5 6 di-(C₁_g)alkylamino or wherein R and R together with the nitrogen atom to which they are attached represent an optionally substituted Cc_₆ aliphatic heterocyclic ring. As examples of suitable groups wherein R and R together with the nitrogen atom to which they are attached form an optionally substituted Ce heterocyclic ring, there may be mentioned morpholinyl, piperidyl, piperazinyl, or pyrollidinyl, each of which may be optionally substituted by halogen or C- , alkyl.

When R⁵ is hydrogen and R⁶ is a group -CR²⁵R²⁶-C0-W or - NR²⁷-C0-W,

25 26 27 R , R and R are preferably hydrogen and W is preferably optionally substituted phenyl or an optionally substituted 5 or 6-membered heterocyclic ring containing from 1 to 3 heteroato s selected from oxygen, nitrogen and sulphur, for instance thienyl or furanyl.

Suitable substituents for W when it is a phenyl or heterocyclyl group include those mentioned previously and especially halogen, C. to C, alkyl, C« to Cg alkoxy, hydroxy, carboxy, C--Cg alkoxycarbonyl, carbamoyl, mono- or di- (C. to Cg) alkyl carbamoyl, sulphamoyl, mono- and di-(C. to Cg) sulphamoyl, cyano, for example m- or p- cyano, nitro, amino, mono- and di- (C. to Cg) alkylamino, C- to C_β acylamino, ureido, C. to Cg alkoxycarbonyla ino, 2,2,2-trichloroethoxycarbonylamino, C. to C, alkanoyl, C- to Cg alkylthio, C- to C_g alkanesulphinyl, and C- to C_g alkanesulphonyl.

Certain compounds of formula (I), (IA) or (IB) are novel.

According to a further aspect of the present invention there is

2 provided a compound of the formula (I) or (IA) or (IB) above wherein R is

3 3 a group CO-XR X, is 0 or S and R is a C- _ιn alkyl group substituted by a 11 J.-J-U -. group -A-R wherein A is 0 or a group S(0) wherein x is 0, 1 or 2 and R is an optionally substituted C. to C. _Q akyl group, an optionally substituted C₂ to C_g alkenyl group, an optionally substitued C₂ to C_g alkynyl group, an optionally substituted phenyl group, an optionally substituted C-_₆ alkyl carbonyl group, optionally substituted C, ₇ cycloalkyl group or an optionally substituted C, ₇ heterocyclic group

3 IΪ provided that R is not a group -(CH₂)₂- when R is ethyl.

Optional substituents may be those indicated previously as suitable for alkyl, alkenyl, alkynyl, phenyl, cycloalkyl or heterocyclyl retrospectively.

3 11

Preferably, R is a C. , alkyl group substituted by a group -A-R

11 wherein A is 0 or a group S(0) wherein x is 0, 1 or 2 and R is an optionally substituted C- to Cg akyl group, an optionally substituted C₂ to

Cg alkenyl group, an optionally substitued C₂ to Cg alkynyl group, an optionally substituted phenyl group, or an optionally substituted C--g alkyl carbonyl group, an optionally substitued C- _β cycloalkyl group or an optionally substituted aliphatic C, ₇ oxygen-containing heterocyclic group,

3 11 provided that R is not a group -(CH₂)₂- when R is ethyl.

In one embodiment of the present invention, R is the group

12 -(CH₉) ,-A-CH=CH-R wherein n' is an integer from 1 to 4 A is 0 or a

12 group S(0) wherein x is 0, 1 or 2 and R is hydrogen or a C. to C, alkyl group.

2 Compounds of formula (I) wherein R is the group C00H and wherein Y represents (IC) or (ID) or (IE) are disclosed in West German

Offenlegungsschriften No. 2726619, 2726618 and 2848687 and European Patent

Application No 79300371.6. Such compounds having the tri-substituted double bond in the E-configuration are referred to as monic acid C, monic acid A and monic acid B respectively. Preferably the compounds of the present invention are derivatives of Monic acid A. However, the compounds of the present invention may exist in the E (natural) and Z (or iso) geometrical forms in respect of the tri-substituted double bond. The stereochemistry of the compound of formula (I) is thus preferably defined such that the moiety (VT) is that moiety having the trivial name "normonyl"

(3-[(2S,3R,4R,5S)-5-{(2S,3S,4S,5S)-2,3-epoxy-5-hydroxy-4-methylhexyl}-

-3,4-dihydroxytetrahydropyran-2-yl]-2-methyl-l(E)-enyl radical) such that

2 when R is the group -C00H, the compound of formula (I) is monic acid A.

Compounds of formula (I) may thus conveniently be named as (1-normonyl) derivatives and esters of monic acid A are conveniently named as monate A esters. It will be appreciated that in compounds of formula (I), the group R may contain one or more chiral centres. The present invention encompasses all such resultant isomeric possibilities.

Particular examples of compounds for use in the composition of the invention are illustrated in Table 1 below wherein the compound is of formula (I) and the stereochemistry of the moiety (VT) is that of the

"normonyl" radical as described above. Table 2 lists examples of compounds for use in the composition of the present invention wherein the compound is of formula (IB), being derivatives of pseudomonic acid. Table 3 lists examples of compound for use in the composition of the present invention wherein the compound is of formula (I) and Y is of formula (IC), being derivatives of monic acid C.

2 It will be readily appreciated that compounds having values of R corresponding to those listed in Table 1 may be prepared wherein the compound is of formula (I) and Y is of the formula (IC) (being derivatives of monic acid C) and wherein the compound is of formula (IB) (being derivatives on pseudomonic acid) and such compounds should be considered as being specifically disclosed herein. Corresponding derivatives of the compounds of formula (IA) and of formula (I) wherein Y is of formula (ID) and (IE) may also be readily prepared and should similarly be considered as being specifically disclosed herein.

TABLE 1

TABLE 1 (Continued)

COMPOUND NUMBER

78 -C0-NH-(CH₂)₂-0-C₂H₅

79 -C0-N(-CH₂-CH=CH₂)₂

80 Structure XII

81 Structure XIII

82 -CO-NH-N(CH₃)₂

83 -C0-NH-N=C(CH₃)₂

84 Structure XIV

85 Structure XV

86 -CO-NH-CH₂-CH=CH₂

87 -CO-N(CH₂-CH₂-OH)₂

88 -C0-0^" (CH₃)₃S⁺

93 -C0-0-CH₂-cyclopropyl

94 -CO-0-(CH₂)₂-0-CH₂-CH=CH-CH₂-CH₂-CH₃

95 -CO-0-(CH₂)₂-0-C(C₃H_y)-CH=CH₂

96 -CO-0^{" +}NH3-CH(CH₃)-CH₃

97 -CO-0^{" +}NH-(C₂H₅)₃

99 -CO-0^{" +}Na

100 -C0-0-CH₂-CH₂-0-CH(CH₃)-CH₃

101 -CO-0-CH₂-CH₂-0-CH₃

102 -CO-0-CH₂-CH₂-0-CH₂-CH₂-CH₃

103 -CO-O-CH(CH₃)-CH₂-0-CH₂-CH₃

104 -C0-0-CH₂-CH₂-0-(cyclopropy1)

105 -CO-0-CH₂-CH(CH₃)-0-CH₂-CH₃

106 -C0-NH-0CH

TABLE 2 (Pseudomonic acid deriatives)

COMPOUND NUMBER

89 -C0-0-CH₂-CH₂-0-CH=CH₂ 90 -C0-0-C₂H₅ 91 -C0-0-(CH₂)₂-0H 92 -C0-N(C₂H₅)₂ 98 -CO-0^{" +} H-(C₂H₅)₃

TABLE 3 (monic acid C deriatives)

COMPOUND NUMBER

107 -C0-0H

108 -C0-0-CH₂-CH₂-0-C₂H₅

Compounds for use in the present invention are either known compounds or may be prepared by methods analogous to those used for the preparation of corresponding known compounds.

The compounds may be regarded as derivatives of monic acid which may be prepared by the selective hydrolysis of pseudomonic acid. A further useful starting material is the ketone which may be obtained from pseudomonic acid by ozonolysis at -50 to -80°C as described for example in GB 1587 060. Derivatives of pseudomonic acid may of course be prepared directly for pseudomonic acid as starting material.

In general it is desirable to protect the hydroxy groups during reactions of the the starting material such as monic acid or derivatives thereof or the corresponding ketone. A wide variety of suitable protecting groups is known and examples, are described for example in EP 0399 645. Particularly suitable protecting groups are silyl groups since these are readily removed under mild conditions. Such groups are introduced by conventional silylating agents, including halosilanes and silazanes. The hydroxyl-protecting groups may subsequently be removed by methods known in the art, including enzymatic methods. For example silyl protecting groups may generally be removed by mild acid hydrolysis followed by alkaline hydrolysis as described for example by J P Clayton, K Luk and N H Rogers in

Chemistry of Pseuodomonic acid, Part II J.C.S. Perkin Trans I, 1979, 308.

The compound No 1 of Table 1 is a known compound and may be prepared for example as described above. A more detailed preparation is given in

Examples 2, 3, 4 and 6 of GB 1,587,058. Salts of the compound of formula

3 (I) wherein X is 0 and R is hydrogen (i.e. salts of Compound No 1 of

Table 1) may also be prepared from monic acid by routine methods as described for example in GB 1,587,058. Typical processes include the reaction of monic acid with a base, for example a hydroxide, carbonate or bicarbonate of the desired cation followed by the removal of water; ion exchange with an appropriate resin; and reaction with amines.

Compound No 2 and Compound No 21 of Table 1 are known compounds and may be prepared for example as described in Examples 24 and 3 respectively of GB 1,587,059. General methods of preparing compounds of formula (I)

2 3 3 wherein R is a group -C0XR and X is 0 and R is an agrochemically acceptable ester-forming radical are also disclosed in GB 1,587,059.

Compound No 3 of Table 1 is a known compound and may be prepared for example using the general methods described in GB 1,587,059 or as more specifically described in J Antibiot. 198841(5).

Compound No 4 of Table 1 is a known compound and may be prepared for example using the methods disclosed in EP 0002 371 as more specifically

2 disclosed in Example 5 thereof. Compounds wherein R in the compound of

3 formula (I) is -CO-XR and X is S may similarly be prepared using the general methods disclosed in EP 0002 371.

Compound Nos 6 and 7 of Table 1 are known compounds and may be prepared for example as described in EP 0025 288 and as more specifically

2 described in Examples 2 and 5 thereof. Compounds wherein R in the compound of formula (I) is a group of formula -C0-0-R and R is a C, ₂n alkyl, C, _g cycloalkyl, C. _2Q alkenyl, aralkyl, cycloalkylalkyl, heterocyclyl or heterocyclylalkyl group which group is substituted with a ketonic oxo group, may be prepared using the general methods described in

EP 0025 288.

Compound No 8 of Table 1 is a known compound and may be prepared for example using the methods disclosed in Japanese patent No 54-151132. Compound No 10 of Table 1 is a known compound and may be prepared for example using the methods disclosed in EP 0052437, and as more specifically described in Example 2 thereof. Compounds of formula (I)

2 3 wherein R is a group -CO-OR may also be prepared as described in Japanese

Patent No 54-12376 or EP 0052437.

Compound No 14 of Table 1 is a known compound and may be prepared for example using the methods disclosed in EP 0087 953, and as more specifically described in Example 21 thereof. Compounds of formula (I)

2 wherein R is a group -C0-NH-CH₂-C0-W as hereinbefore defined may be prepared using the general methods set out in EP 0087 953 where it is an

2 intermediate in the manufacture of the compounds wherein R is a heterocyclic group -R having the formula (III) above which may similarly be prepared as described in EP 0087 953. Thus for example, Compound No 19 may be prepared using an analogous method to that described in Example 14 of EP 0087 953 (5-methyl-2-(l-normon-2-yl)oxazole or as more specifically described in J Chem Soc, Perkin Trans. I 1989 (11) 2059-63. Similarly,

Compound No 22 of Table 1 may be prepared as described in Example 10 of

EP 0087 953.

Compound No 15 of Table 1 is a known compound and may be prepared for example using the methods disclosed in EP 0123378, and as more specifically disclosed in Example 8 thereof. Compounds of general formula

2 (I) wherein R is a group -C0-NH-NH₂ or -C0-NH-NH-C0-W as hereinbefore defined may be prepared using the general methods described in EP 0 123 378 where such compounds are intermediates to heterocyclic derivatives which themselves provide further examples of compounds of the general formula (I)

2 4 wherein R is a group -R .

Compound No 18 of Table 1 is a known compound and may be prepared for example using the methods disclosed in EP 0399 645, and as more specifically disclosed in Example 16 thereof. Compounds of general formula

2 2 44

( (II)) wwhheerreeiinn RR iiss aa ggrroouupp --RR hhaavviinngg tthhee ff<ormula (II) above may be prepared using the general methods of EP 0399 645.

2 Compound of formula (I), (IA) or (IB) wherein R is a group of formula

-C0NR R may be prepared using the general methods described in

EP 0001914.

In general therefore, typical processes for the manufacture of

2 3 compounds of formula (I), (IA) or (IB) wherein R is the group -C00R include the reaction of a salt of monic acid (A, B or C) or pseudomonic

3 acid, for example an alkali metal salt, with a compound R -L wherein L is a leaving group such as halogen or mesolate to form an ester. The reaction suitably takes place in a solvent such as dimethylformamide or dimethylsulphoxide at a temperature in the range 10°C to 100°C and optionally in the presence of a co-solvent such as hexamethylenephosphonamide or N,N-dimethylpropyleneurea and optionally in the presence of a catalyst, such as an iodide catatlyst. If desired the salt of monic acid or pseudomonic acid may be prepared in situ, for example by treatment of the acid with the appropriate base such as the carbonate.

2 Alternatively, compounds of formula (I), (IA) or (IB) wherein R is 5 6 the group -COXR or -CONR R may be prepared by the action of a compound

3 5 6 R XH or R R NH on a monic or pseudomonic acid or a simple activated derivative thereof. Suitably the raction takes place in a solvent such as tetrahydrofuran, diethyl ether, dichloromethane or chloroform and at a temperature in the range from -10°C to 70°C.

Other suitable methods of preparation of the compounds for use in the composition of the present invention are described in the literature with specific reference to the patents and papers cited above.

The compounds for use in the compositions of the present invention are active against a broad range of weed species including monocotyledonous and dicotyledonous species. Many compounds show good selectivity in crops, particularly wheat, barley, maize, oil seed rape, sugar beet and rice. The compounds for use in compositions of the present invention are preferably applied directly to unwanted plants (post-emergence application) but they may also be applied to the soil before the unwanted plants emerge (pre-emergence application).

Thus acording to a further aspect of the present invention there is provided a process of severely damaging or killing unwanted plants, which comprises applying to the plants or the the growth medium of the plants a herbicidally effective amount of a compound of the formula (I) or (IA) or

2 (IB) as hereinbefore defined wherein R is as hereinbefore defined.

Novel compounds of the present invention are preferably used in the form of a composition comprising a compound of formula (I) in admixture with a carrier comprising a solid or liquid diluent.

Suitable compositions of the present invention include both dilute compositions, which are ready for immediate use, and concentrated compositions, which require to be diluted before use, usually with water. Preferably the compositions contain from 0.01% to 90 by weight of the active ingredient. Dilute compositions ready for use preferably contain from 0.01 to 2% of active ingredient, while concentrated compositions may contain from 20 to 90% of active ingredient, although from 20 to 70% is usually preferred.

The solid compositions may be in the form of granules, or dusting powders wherein the active ingredient is mixed with a finely divided solid diluent, e.g. kaolin, bentonite, kieselguhr, dolomite, calcium carbonate, talc, powdered magnesia, Fuller's earth and gypsum. They may also be in the form of dispersible powders or grains, comprising a wetting agent to facilitate the dispersion of the powder or grains in liquid. Solid compositions in the form of a powder may be applied as foliar dusts.

Liquid compositions may comprise a solution or dispersion of an active ingredient in water optionally containing a surface-active agent, or may comprise a solution or dispersion of an active ingredient in a water-immiscible organic solvent which is dispersed as droplets in water.

Surface-active agents may be of the cationic, anionic, or non-ionic type or mixtures thereof. The cationic agents are, for example, quaternary ammonium compounds (e.g. cetyltrimethylammonium bromide). Suitable anionic agents are soaps; salts of aliphatic mono ester of sulphuric acid, for example sodium lauryl sulphate; and salts of sulphonated aromatic compounds, for example sodium dodecylbenzenesulphonate, sodium,calcium, and ammonium lignosulphonate, butylnaphthalene sulphonate, and a mixture of the sodium salts of diisopropyl and triisopropylnaphthalenesulphonic acid. Suitable non-ionic agents are the condensation products of ethylene oxide with fatty alcohols such as oleyl alcohol and cetyl alcohol, or with alk lphenols such as octyl- or nonyl- phenol (e.g. Agral 90) or octyl-cresol. Other non-ionic agents are the partial esters derived from long chain fatty acids and hexitol anhydrides, for example sorbitaπ monolaurate; the condensation products of the partial ester with ethylene oxide; the lecithins; and silicone surface active agents (water soluble surface active agents having a skeleton which comprises a siloxane chain e.g. Silwet L77). A suitable mixture in mineral oil is Atplus 411F.

The aqueous solutions or dispersions may be prepared by dissolving the active ingredient in water or an organic solvent optionally containing wetting or dispersing agent(s) and then, when organic solvents are used, adding the mixture so obtained to water optionally containing wetting or dispersing agent(s). Suitable organic solvents include, for example, ethylene di-chloride, isopropyl alcohol, propylene glycol, diacetone alcohol, toluene, kerosene, methylnaphthalene, the xylenes and trichloroethylene.

The compositions for use in the form of aqueous solutions or dispersions are generally supplied in the form of a concentrate containing a high proportion of the active ingredient, and the concentrate is then diluted with water before use. The concentrates are usually required to withstand storage for prolonged periods and after such storage, to be capable of dilution with water to form aqueous preparations which remain homogeneous for a sufficient time to enable them to be applied by conventional spray equipment. Concentrates conveniently contain 20-90%, preferably 20-70%, by weight of the active ingredient(s). Dilute preparations ready for use may contain varying amounts of the active ingredient(s) depending upon the intended purpose; amounts of 0.01% to 10.0% and preferably 0.1% to 2%, by weight of active ingredient(s) are normally used.

A preferred form of concentrated composition comprises the active ingredient which has been finely divided and which has been dispersed in water in the presence of a surface-active agent and a suspending agent. Suitable suspending agents are hydrophilic colloids and include, for example, polyvinylpyrrolidone and sodium carboxymethy1cellulose, and the vegetable gums, for example gum acacia and gum tragacanth. Preferred suspending agents are those which impart thixotropic properties to, and increase the viscosity of the concentrate. Examples of preferred suspending agents include hydrated colloidal mineral silicates, such as montmorillonite, beidellite, nontronite, hectorite, saponite, and saucorite. Bentonite is especially preferred. Other suspending agents include cellulose derivatives and polyvinyl alcohol.

The rate of application of the compounds of the invention will depend on a number of factors including, for example, the compound chosen for use, the identity of the plants whose growth is to be inhibited, the formulations selected for use and whether the compound is to be applied for foliage or root uptake. As a general guide, however, an application rate of from 0.0001 to 20 kilograms per hectare is suitable while from 0.001 to 10, for example 0.001 to 2 kilograms per hectare may be preferred.

The compositions of the invention may comprise, in addition to one or more compounds of the invention, one or more compounds not of the invention but which possess biological activity. Accordingly in yet a still further embodiment the invention provides a herbicidal composition comprising a mixture of at least one herbicidal compound of formula (I) (IA) or (IB) as hereinbefore defined with at least one other herbicide.

The other herbicide may be any herbicide not having the formula (I) (IA) or (IB). It will generally be a herbicide having a complementary action in the particular application.

Examples of useful complementary herbicides include:

A. benzo-2,l,3-thiadiazin-4-one-2,2-dioxides such as bentazone;

B. hormone herbicides, particularly the phenoxy alkanoic acids such as MCPA, MCPA-thioethyl, dichlorprop, 2,4,5-T, MCPB, 2,4-D, 2,4-DB, mecoprop, trichlopyr, clopyralid, and their derivatives (eg. salts, esters and amides);

C. 1,3 dimethylpyrazole derivatives such as pyrazoxyfen, pyrazolate and benzofenap;

D. Dinitrophenols and their derivatives (eg. acetates) such as dinoterb, dinoseb and its ester, dinoseb acetate;

E. dinitroaniline herbicides such as dinitramine, trifluralin, ethalflurolin, pendimethalin, oryzalin;

F. arylurea herbicides such as diuron , flumeturon, metoxuron, neburon, irk " -k isoproturon , chlorotoluron , chloroxuron, linuron, monolinuron, chlorobromuron, daimuron, methabenzthiazuron;

G. phenylcarbamoyloxyphenylcarbamates such as phenmedipham and desmedipham;

H. 2-phenylpyridazin-3-ones such as chloridazon and norflurazon; I. uracil herbicides such as lenacil , bromacil and terbacil; J. triazine herbicides such as atrazine , simazine, aziprotryne, cyanazine, pro etryn, dimetha etryn, simetryne, and terbutryn; K. phosphorothioate herbicides such as piperophos, bensulide, and butamifos; L. thiocarbamate herbicides such as cycloate, vernolate, olinate,

^■k * thiobencarb, butylate , EPTC , tri-allate, di-allate, esprocarb, tiocarbazil, pyridate, prosulfocarb and dimepiperate;

M. l,2,4-triazin-5-one herbicides such as metamitron and metribuzin;

N. benzoic acid herbicides such as 2,3,6-TBA, dicamba and chloramben;

0. anilide herbicides such as pretilachlor, butachlor, alachlor, propachlor, propanil, metazachlor, metolachlor, acetochlor , and dimethachlor; ddiihhaalloobbeeinzonitrile herbicides such as dichlobenil, bromoxynil and ioxynil; Q. haloalkanoic herbicides such as dalapon, TCA and salts thereof;

R. diphenylether herbicides such as lactofen, fluroglycofen or salts or ester thereof, nitrofen, bifenox, aciflurofen and salts and esters thereof, oxyfluorfen, fomesafen, chlornitrofen and chlomethoxyfen;

S. phenoxyphenoxypropionate herbicides such as diclofop and esters thereof such as the methyl ester, fluazifop and esters thereof, haloxyfop and esters thereof, quizalofop and esters thereof and fenoxaprop and esters thereof such as the ethyl ester;

T. cyclohexanedione herbicides such as alloxydim and salts thereof, irk sethoxydim, cycloxydim, tralkoxydim , and clethodim;

U. sulfonyl urea herbicides such as chlorsulfuron, sulfometuron, metsulfuron and esters thereof; benzsulfuron and esters thereof such as DPX-M6313, chlorimuron and esters such as the ethyl ester thereof pirimisulfuron and esters such as the methyl ester thereof, 2-[3-(4-methoxy-6-methyl-l,3,5- triazin-zyl)-3-methylureidosulphonyl) benzoic acid esters such as the methyl ester thereof (DPX-LS300) and pyrazosulfuron;

V. imidazolidinone herbicides such as imazaquin, imazamethabenz, imazapyr and isopropylammonium salts thereof, imazethapyr;

W. arylanilide herbicides such as flamprop and esters thereof, benzoylprop-ethyl, diflufenican ;

X. amino acid herbicides such as glyphosate and glufosinate and their kk kk salts and esters , sulphosate (glyphosate trimesium) and bialaphos; Y. organoarsenical herbicides such as monosodium methanearsonate (MSMA); Z. herbicidal amide derivative such as napropamide, propyzamide, carbeta ide, tebutam, bromobutide, isoxaben, naproanilide and naptalam; AA triketones such as sulcotrione; BB. miscellaneous herbicides including ethofumesate, cinmethylin, difenzoquat and salts thereof such as the methyl sulphate salt, clomazone, oxadiazon, bromofenoxim, barban, tridiphane, flurochloridone, quinchlorac and mefanacet; CC. Examples of useful contact herbicides include: bipyridylium herbicides such as those in which the active entity is paraquat and those in which the active entity is diquat;

* These compounds are preferably employed in combination with a safener such as dichlormid.

** These compounds have been demonstrated to exhibit additive and in several instances synergystic effects when applied in admixture with compounds of the present invention.

It is an advantage of preferred compounds of the present invention that they are compatible with a wide range of co-herbicides such as those listed above and may exhibit additive or synergystic effects in such mixtures.

The invention is illustrated by the following Examples.

EXAMPLE 1

The compounds listed in Table 1 were characterised by their NMR spectrum. In each case, the moiety derived from monic acid A (i.e. the

"normonyl" group of structure VI below) was characterised by a complex but readily identifiable spectrum which corresponded to that of Compound No 1, monic acid itself. Table II below lists the visible characterising

2 features of the spectrum attributable to the different groups R although key peaks derived from the monic acid moiety may be included for comparative identification. The solvent in which the spectrum was recorded is also given.

TABLE II

H NMR δ

5.9(lH,m); 5.2(2H,m); 4.6(2H,d)

4.0(2H,t); 3.5(2H,m)

2.3(3H,s)

6.5(lH,t); 4.3(2H,m); 3.9(2H,m); 3.8(2H,m)

4.0(2H,t); 2.2(3H,s)

8.0-7.5(5H,m); 4.2(2H,t); 2.2(2H,t)

4.6(2H,s)

4.8(2H,s)

7.7-7.4(4H,m); 5.2(2H,s)

7.6-7.2(4H,m); 5.1(2H,s)

7.3-7.1(4H,m); 5.1(2H,s); 2.2(3H,s) 7.4(4H,s); 5.1(2H,s); 4.7(2H,d) TABLE II (Continued)

Compound Solvent H NMR δ Number

14 CDCl- 8.1-7.8(4H,m); 4.8(2H,d) 15 dg-DMSO 10.2(lH,s); 9.8(lH,s); 7.9(lH,s); 7.2(lH,d);

6.6(lH,s)

16 CDC1, 9.8(lH,s); 9.6(lH,s); 7.6(2H,d); 6.6(2H,d);

2.9(6H,s)

4.1(2H,t); 3.4(2H,t)

7.8(lH,s); 7.5(lH,s); 7.1(lH,d); 6.6(lH,s)

6.8(lH,s); 1.2(3H,t)

4.1(2H,t)

3.7(3H,s) 8.0(2H,d); 7.8(2H,d); 7.6(lH,s)

EXAMPLE 2

This Example illustrates the preparation of 2-Vinyloxyethyl monate A (Compound No 5 of Table 1).

Sodium monate A (lg, 2mM) was dissolved in di ethylformamide (25ml) and stirred with 2-chloroethylvinyl ether (0.6ml, 6mM), hexamethyl- phosphoramide (3 drops) and sodium iodide (0.9g) at 80°C for 6 hours. After evaporation in vacuo the residue was partitioned between ethyl acetate and brine, and the aqueous phase further extracted with ethyl acetate (3x50ml). The combined organic fractions were washed with 10% sodium thiosulphate solution, saturated sodium bicarbonate solution and brine, dried (MgSO,) and evaporated in vacuo. Separation on silica (type 60, 20g) eluting with 0 to 4% methanol/CHCl- gave the product, which crystallised on standing to give a solid of melting point 78-80°C. The NMR spectrum was as indicated in Example 1.

EXAMPLE 3

This Example illustrates the preparation of cyanomethyl monate A (Compound No 9 of Table 1).

A solution containing sodium monate A (2.00g, 5.4mmol), chloroacetonitrile (0.35ml, 5.4mmol) and dimethylformamide (50ml) was stirred 1 hour at 80° and then evaporated in vacuo. The residue was taken up in ethyl acetate, which was washed with aqueous sodium bicarbonate and then brine, dried (MgSO,), evaporated in vacuo, and purified by chromatography (0 to 4% methanol in chloroform, 20g silica gel) to give the desired product as a clear oil. The NMR spectrum was as indicated in Example 1.

EXAMPLE 4

This Example illustrates the preparation of 3-bromobenzyl monate A (Compound No 11 of Table 1).

A solution containing sodium monate A (l.lgm 3mmol), m-bromobenzyl bromide (0.75g, 3mmol), and dimethylformamide (35ml) was stirred at 20°C for 5 hours and then evaporated in vacuo. The resiude was taken up in ethyl acetate/brine, the organic layer washed with aqueous sodium bicarbonate, then brine, dried (MgSO,), evaporated in vacuo, and purified by chromatography (0 to 6% methanol in dichloromethane, 20g silica gel) to give the desired product as a colourless oil which solidified to yield white powder of melting point 91°C-92°C. The NMR spectrum was as indicated in Example 1.

EXAMPLE 4

This Example illustrates the preparation of 3-methylbenzyl monate A (Compound No 12 of Table 1).

A solution containing sodium monate A (0.73g, 2mmol), α-bromo-m-xylene (0.37g, 2mmol) and dimethylformamide (25ml) was stirred at 20°C for 17 hours and then evaporated in vacuo. The residue was taken up in ethyl acetate/brine, the organic phase washed with aqueous sodium bicarbonate and then brine, dried (MgSO,) and evaporated in vacuo. The residual oil was purified by chromatography (0 to 4% methanol in dichloromethane, 15g silica gel) to yield the desired product as a colourless oil. The NMR spectrum was as indicated in Example 1.

EXAMPLE 5

This Example illustrates the preparation of 4-hydroxymethylbenzyl monate A (Compound No 13 of Table 1).

£-Toluic acid (13.6g, lOOmmol) was refluxed in methanol (95ml) and concentrated sulphuric acid (5ml) for Vk hours. The reaction was evaporated to half volume, poured into water, extracted with ethyl acetate, dried (MgSO,), and evaporated in vacuo. To the residue was added N-bromosuccinimide (17.8g, lOOmmol), benzoyl peroxide (lOOmg) and carbon tetrachloride (50ml) and refluxed for 2-k hours. The reaction was then filtered, and the filtrate evaporated in vacuo. The product, methyl-4-bromomethylbenzoate (9.2g, 40mmol) in toluene (80ml) was cooled to -30°C and a solution of diisobutyl aluminium hydride in toluene (60ml, 25%, δOmmol) was added dropwise and stirred for 1 hour. The solution was allowed to warm to room temperature and stirred a further 2 hours. The reaction was then quenched with methanol, filtered, and the filtrate washed with aqueous sodium bicarbonate solution and then brine. The orgnaic layer was dried (MgSO,) and evaporated in vacuo to yield 4-bromomethylbenzyl alcohol.

A solution containing sodium monate A (4mmol) and 4-bromomethylbenzyl alcohol (4mmol) in dimethylformamide (60ml) was stirred overnight at room temperature, and then evaporated in vacuo. The residue was taken up in ethyl acetate/brine, washed with aqueous sodium bicarbonate and then brine, dried and evaporated. The residue was purified by chromatography, eluting with methanol/dichloromethane mixtures to yield a colourless oil. The NMR spectrum was as indicated in Example 1.

EXAMPLE 6

This Example illustrates the preparation of 4-dimethylaminobenzoyl- monhydrazide A (Compound No 16 of Table 1).

Monic acid A (3.44g, lOmmol) was dissolved in tetrahydrofuran (100ml) and cooled to 0°C. Triethylamine (1.5ml, llmmol) and isobutylchloroformate (1.4ml, llmmol) were added and stirred for 30 minutes. Dimethylamino- benzahydrazide (1.79g, lOmmol) was added and the reaction mixture stirred for 5 hours. The reaction mixture was then filtered and evaporated under reduced pressure. The residue was crystallised from ether to yield the desired product as a white solid of melting point 116-118°C. The NMR spectrum was as indicated in Example 1.

EXAMPLE 7

This Example illustates the preparation of l-bromo-8-octyl monate A (Compound No 17 of Table 1).

A solution containing sodium monate A (l.Og, 2.7mmol) and 1,8-dibromooctane (0.75g, 2.7mmol) in dimethylformamide (5ml) was stirred overnight at room temperature and then evaported under reduced pressure. The residue was dissolved in ethyl acetate/water and the organic layer washed with water, dried (MgSO,) and evaporated under reduced pressure. The resulting residue was purified by column chromatography (silica gel, eluting with 0 to 3% methanol in dichloromethane) to yield the desired product as an oil. The NMR spectrum was as indicated in Example 1. EXAMPLE 8

The Example illustrates the preparation of cetyl monate A (Compound No 20 of Table 1).

Monic acid A (25.8g, 75mmol), potassium carbonate (10.5g, 76mmol), sodium iodide (15.Og, lOOmmol) and cetyl bromide (45ml, 147mmol) were stirred in dimethylformamide (750ml) and hexamethylphosphoramide (150 drops) for 24 hours. The mixture was diluted with ethyl acetate (1.51), washed with water (4 x 0.51) and brine, dried and evaporated. The residue was purified on silica (1200g), eluting with 5% methanol in chloroform, to give a fine white powder. This was recrystallised from ethyl ^" acetate/hexane to give the desired product. The NMR spectrum was as indicated in Example 1.

EXAMPLE 9

This Example illustrates the preparation of pent-4-enyl monate A (Compound No 25 of Table I).

Sodium monate A (160mg, 0.44mM) was dissolved in dimethylformamide (2ml) and stirred with l-bromopent-4-ene (131mg, 0.88mM) and N,N-dimethylpropyleneurea (0.38ml) at room temperature for 4 hours and then at 70°C for 2 hours. Volatile components were removed by evaporation in vacuo. Separation on silica eluting with 55:45 acetone/hexane gave the desired product as a colourless syrup.

-R NMR δ(CDCl₃): 5.82 (1H, m), 5.77 (1H, s), 5.08 (1H, d), 5.00 (1H, d), 4.11 (2H, t), 2.21 (3H, s), 1.22 (3H, d), 0.95 (3H, d).

EXAMPLES 10 TO 15

The following compounds were prepared using the general method of Example 9:

4-Methox benzyl monate A (Compound No 55 of Table I)

~E NMR δ(CDCl₃) 7.30 (2H, d), 6.88 (2H, d), 5.79 (1H, s), 5.07 (2H, s), 3.90 (3H, s), 2.21 (3H, s), 1.22 (3H, d), 0.92 (3H, d).

3-Nitrobenzyl monate A (Compound No 70 of Table I) ~ ~EE NNMMRR δδ((CCDDCCll₃₃)) 88..2288 ((11HH,, ss)),, 88..2200 ((11HH,, dd)),, 77..77(0 (lH, d), 7.54 (1H, t), 5.80 (2H, s), 2.22 (3H, s), 1.21 (3H, d), 0.93 (3H, d),

Propargyl monate A (Compound No 71 of Table I)

^Η NMR δ(CDCl₃) 5.80 (1H, s), 4.71 (2H, s), 2.22 (3H, s), 1.21 (3H, d),

0.94 (3H, d). Ethyl acet-2-yl monate A (Compound No 72 of Table I) ^lB. NMR δ(CDCl₃) 5.89 (1H, s), 4.63 (2H, abq), 4.22 (2H, q), 2.22

(3H, s), 1.29 (3H, t), 1.22 (3H, d), 0.91 (3H, d).

Decyl monate A (Compound No 73 of Table I)

~E NMR δ(CDCl₃) 5.78 (1H, s), 4.08 (2H, t), 2.21 (3H, s), 1.21 (3H, d),

0.95 (3H, d), 0.87 (3H, t).

2-Phenoxyethoxy monate A (Compound No 27 of Table 1)

^XH NMR δ(CDCl₃) 7.29 (2H, t), 6.91 (3H, m), 5.81 (1H, s) 4.46 (3H, t), 4.19 (3H, t), 2.22 (3H, s), 1.21 (3H, d), 0.92 (3H, d).

EXAMPLE 16

This Example illustrates the preparation of prop-2-yl monate A (Compound No 36 of Table I).

Sodium monate A (200mg, 0.55mM) was dissolved in dimethylformamide (2ml) and stirred with 2-bromopropane (136mg, l.llmM), N,N-dimethylpropyleneurea (0.476g) and sodium iodide (166mg, l.llmM) at room temperature for 1.5 hours and then left to stand for 4 days. Volatile components were removed by evaporation in vacuo. Separation on silica eluting with 55:45 acetone/hexane gave the desired product as a colourless syrup.

"B NMR δ(CDCl₃) 5.72 (1H, s), 5.02 (1H, m), 2.21 (3H, s), 1.24 (6H, d), 1.22 (3H, d), 0.94 (3H, d).

EXAMPLES 17 TO 19

The following compounds were prepared in a manner corresponding to that to Example 16:-

2-Ethoxyethyl monate A (Compound No 26 of Table I) NMR δ(CDCl₃) 5.81 (1H, s), 4.26 (2H, t), 3.66 (2H, t), 3.54 (2H, t),

2.21 (3H, s), 1.22 (3H, m), 1.21 (3H, d), 0.94 (3H, d).

Pent-4-ynyl monate A (Compound No 31 of Table I) NMR δ(CDCl₃) 5.78 (1H, s), 4.20 (2H, t), 2.21 (3H, s), 1.22 (3H, d),

0.94 (3H, d).

Ethyl propion-2-yl monate A (Compound No 45 of Table I), obtained as a mixture of diastereoisomers.

~E NMR δ(CDCl₃) 5.86 (1H, s), 5.09 (1H, m), 4.21 (2H, q), 2.21 (3H, s), 1.50 (3H, d) , 1.25 (3H, t) , 1.22 (3H, d) , 0.92 (3H, d) .

EXAMPLE 20

This Example illustrates the preparation of 2-(4-chlorophenoxy)ethyl monate A (Compound No 28 of Table I)

Monic acid A (200mg, 0.58mM) was dissolved in dimethylformamide (1ml) and stirred with 2-(4-chlorophenoxy)ethyl bromide (273mg, l.lόmM) and N,N- di ethylpropyleneurea (510mg, 3.98mM). Potassium carbonate (120mg, 0.87mM) was added and the mixture stirred at room temperature for 1 hour and at 80°C for 1.5 hours. Volatile components were removed by evaporation in vacuo. Separation on silica eluting with 55:45 acetone/hexane gave the desired product as a gum.

-R NMR δ(CDCl₃) 7.25 (2H, d), 6.82 (2H, d), 5.80 (1H, s), 4.40 (2H, m), 4.16 (2H, m), 2.22 (3H, s), 1.21 (3H, d), 0.93 (3H, d).

EXAMPLES 21 TO 32

The following compounds were prepared using the general method of Example 20:

2-((2-methoxy)ethoxy)ethyl monate A (Compound No 42 of Table I) NMR δ(CDCl₃) 5.81 (1H, s), 4.27 (2H, t), 3.72 (2H, t), 3.65 (2H, m), 3.55 (2H, ), 3.40 (3H, s), 2.21 (3H, s), 1.21 (3H, d), 0.95 (3H, d).

A (1:4) mixture of l-methylprop-2-enyl monate A (Compound No 49 of Table I - itself a mixture of diastereoisomers) and but-2-enyl monate A (Compound No 48 of Table I - itself a mixture of geometrical isomers)

l-methylprop-2-enyl monate A hi NMR δ(CDCl₃) 5.78 (1H, m), 5.39 (1H, m), 5.25 (1H, m), 5.15 (1H, m),

2.21 (3H, s), 1.70 (3H, s), 1.21 (3H, d), 0.99 and 0.80 (3H, 2xd).

But-2-enyl monate A NMR δ(CDCl₃) 5.78 (1H, m), 5.60 (1H, m), 4.63 and 4.52 (2H, 2xd),

2.21 (3H, s), 1.21 (3H, d), 0.95 (3H, d).

2-(Ethoxycarbonylmethoxy)ethyl monate A (Compound No 30 of Table 1) hi NMR δ(CDCl₃) 5.80 (1H, s), 4.29 (2H, t), 4.23 (2H, q), 4.14 (2H, s),

3.80 (2H, t), 2.23 (3H, s), 1.28 (3H, t), 1.23 (3H, d), 0.94 (3H, d). 2-(Acetoxy)ethyl monate A (Compound No 29 of Table 1)

-R NMR δ(CDCl₃) 5.78 (1H, s), 4.28 (4H, s), 2.23 (3H, s), 2.08 (3H, s),

1.22 (3H, d), 0.94 (3H, d).

2-(Carbamoylmethoxy)ethyl monate A (Compound No 46 of Table 1)

-E NMR δ(CDCl₃) 6.65 (1H, s), 6.50 (1H, s), 5.86 (1H, d), 4.54 (2H, s),

2.22 (2H, s), 1.21 (3H, d), 0.92 (3H, d).

3-Chloroprop-2-en-l-yl monate A (Compound No 47 of Table 1) NNMMRR δδ((CCDDCCll₃₃)) 66..3377--55..9911 ((22HH,, mm)),, 55..7799 ((I1IH, s), 5.81 & 4.59 (2H, 2 d), 2.21 (3H, s), 1.22 (3H, d), 0.94 (3H, d).

Ethyl monate A (Compound No 35 of Table 1) NMR δ(CDCl₃) 5.75 (1H, s), 4.12 (2H, q), 2.21 (3H, s), 1.29 (3H, t),

1.21 (3H, d), 0.93 (3H, d).

Butyl monate A (Compound No 37 of Tώble 1)

~E NMR δ(CDCl₃) 5.75 (1H, s), 4.10 (2H, t), 2.20 (3H, s), 1.65 (2H, m),

1.38 (2H, m), 1.21 (3H, d), 0.92 (6H, m).

Cyclohexyl monate A (Compound No 39 of Table 1) NMR δ(CDCl₃) 5.73 (1H, s), 4.78 (1H, m), 2.21 (3H, s), 1.80-1.20

(10H, s), 1.22 (3H, d), 0.94 (3H, d).

Ethoxymethyl monate A (Compound No 76 of Table 1). NMR δ(CDCl₃) 5.79 (1H, s), 5.30 (2H, s), 2.22 (3H, s), 1.22 (3H, d),

0.92 (3H, d).

EXAMPLE 33 This Example illustrates the preparation of 2-(allyloxy)ethyl monate A (Compound No 23 of Table I)

Stage 1 Preparation of l-Mesyloxy-2-allyloxyethane

2-Allyloxyethanol (5.0g, 49mM) was stirred with triethylamine (5.2g, 51mM) in dichloromethane (25ml) at 0°C under nitrogen. Methanesulphonyl chloride (5.61g, 49mM) was added slowly with stirring. The cooling bath was removed at the mixture stirred at room temperature for a further 1 hour. Volatile components were removed by evaporation in vacuo. The residue was partitioned between diethyl ether and water. The organic fraction was washed twice with water and once with brine, dried (MgS04) and evaporated in vacuo. The product was a yellow oil.

Stage 2 Preparation of 2-(allyloxy)ethyl monate A Sodium monate A (165mg, 0.45mM) was dissolved in dimethylformamide (2ml) and stirred with l-mesyloxy-2-allyloxyethane (162mg, 0.90mM) and N,N-dimethylpropyleneurea (0.39ml) at room temperature for 19 hours. Volatile components were removed by evaporation in vacuo. Separation on silica eluting with 55:45 acetone/hexane gave the desired product as a colourless oil. hi NMR δ(CDCl₃) 5.90 (1H, ), 5.81 (1H, s), 5.27 (1H, d), 5.20 (1H, d), 4.27 (2H, t), 4.05 (2H, d), 3.75 (2H, t), 2.21 (3H, s), 1.22 (3H, d), 0.92 (3H, s).

EXAMPLES 34 TO 37 The following compounds were prepared using the general method of Example 33:-

3-Vinyloxypropyl monate A (Compound No 33 of Table 1) hi NMR δ(CDCl₃) 6.46 (1H, dd), 5.76 (1H, s), 4.19 (3H, m), 4.01

(1H, dd), 3.79 (2H, t), 2.21 (3H, s), 1.23 (3H, d), 0.95 (3H, d).

2-(3-Chloroprop-2-en-l-yloxy)ethyl monate A No 44 of Table 1) hi NMR δ(CDCl₃) 6.20 (1H, d), 5.95 (1H, q), 5.81 (1H, s), 4.27 (4H, m),

3.70 (2H, t), 2.22 (3H, s), 1.22 (3H, d), 0.94 (3H, d).

4-Vinyloxybut-l-yl monate A (Compound No 32 of Table 1) NMR δ(CDCl₃) 6.46 (1H, abq), 5.74 (1H, s), 4.11 (2H, m), 2.21

(3H s), 1.20 (3H, d), 0.92 (3H, d).

2-(prop-2-yn-l-yloxy)ethyl monate A (Compound No 43 of Table 1) NMR δ(CDCl₃) 5.80 (1H, s), 4.28 (2H, t), 4.21 (2H, d), 3.79(2H, t) 2.48 (1H, t), 2.21 (3H, s), 1.21 (3H, d), 0.94 (3H, d).

EXAMPLE 38

This Example illustrates the preparation of N,N-Diethyl-monicamide A (Compound No 63 of Table I)

Monic acid A (200mg, 0.58mM) was dissolved in tetrahydrofuran (5ml) and cooled to -10°C under nitrogen. Triethylamine (59mg, 0.58mM) and isobutylchloroformate (80mg, 0.58mM) were added and stirred for 30 minutes. A solution of diethylamine (47mg, 0.58mM) in tetrahydrofuran (0.5 ml) was added an the reaction mixture stirred for 1 hour and then at room temperature for 2 hours. The reaction mixture was filtered and evaporated in vacuo. Thin layer chromatography indicated that the reaction was incomplete so further diethylamine (20mg) in tetrahydrofuran (3ml) was added and the mixture stood at room temperature overnight. Volatile components were removed by evaporation in vacuo. The residue was taken up in water (10ml) and extracted with chloroform (3x10ml). The combined organic extracts were dried (MgS04) and evaporated in vacuo. The resulting residue was purified by column chromatography (silica gel, eluting with methanol/chloroform 1:9) to give the desired product as a colourless gum. NMR δ(CDCl₃) 5.87 (1H, s), 1.91 (3H, s), 1.21 (3H, d), 1.12 (6H, m), 0.92 (3H, d).

EXAMPLES 39 TO 56 The following compound was prepared using the general method of Example 38:

Monic acid A morpholine amide (Compound No 64 of Table I) ^lE NMR δ(CDCl₃) 5.81 (1H, s), 3.67-3.47 (8H, m), 1.90 (3H, s), 1.21 (3H, d), 0.94 (3H, d).

N-(2,4-Dichlorophenyl)-N-methylmonic amide A (Compound No 60 of Table 1) hi NMR δ(CDCl₃) 7.50-7.15 (3H, m), 5.49 (1H, s), 3.20 (3H, s), 2.18 (3H, s), 1.22 (3H, d), 0.95 (3H, d).

N-(2-Hydroxyethyl)monicamide A (Compound No 77 of Table 1).

~E NMR δ(dg-DMSO) 7.89 (1H, t), 5.81 (1H, s), 4.51 (4H, m), 2.21 (3H, s),

1.21 (3H, d), 0.95 (3H, d).

N-(2-Ethoxyethyl)monicamide A (Compound No 78 of Table 1).

"E NMR δ(dg-DMSO) 6.21 (1H, t), 5.68 (1H, s), 3.62-3.42 (6H, m), 2.20

(3H, s), 1.20 (6H, m), 0.92 (3H, d).

N-(Ethoxycarbonylmethyl)monicamide A (Compound No 66 of Table 1) ^XH NMR δ(CDCl₃) 6.24 (1H, t), 5.73 (1H, s), 4.23 (2H, q), 4.0< 2.19 (3H, s), 1.30 (3H, t), 1.22 (3H, d), 0.92 (3H, d).

Monicamide A (Compound No 61 of Table 1)

-E NMR δ(d₄-MeOH) 5.93 (1H, s), 2.29 (3H, s), 1.35 (3H, d), 1.10 (3H, d). N-(2,4-Dichlorophenyl)monicamide A (Compound No 58 of Table 1) hi NMR δ(d -MeOH) 7.99 (IE, d), 7.63 (IH, d), 7.45 (IH, dd), 6.20 (IH, s),

2.38 (3H, s), 1.33 (3H, d), 1.10 (3H, d).

N,N-bisallylmonicamide A (Compound No 79 of Table 1). ^lE NMR δ(CDCl₃) 5.89 (IH, s), 5.76 (2H, m), 5.16 (4H, m), 1.97 (3H, s),

1.22 (3H, d), 0.93 (3H, d).

Monic acid A piperidine amide (Compound No 80 of Table 1).

-R NMR δ(CDCl₃) 5.81 (IH, s), 3.50 (4H, m), 1.85 (3H, s), 1.60 (6H, m),

1.21 (3H, d), 0.92 (3H, d).

Monic acid A N-methylpiperazine amide (Compound No 81 of Table 1).

~E NMR δ(d₄-MeOH) 5.99 (IH, s), 3.72 (4H, m), 2.56 (4H, t), 2.44 (3H, s)_;

1.97 (3H, s), 1.32 (3H, d), 1.06 (3H, d).

N,N-Dimethylmonichydrazide A (Compound No 82 of Table 1).

-R NMR δ(CDCl₃) 5.52 (IH, s), 2.40 (6H, s), 2.04 (3H, s), 1.10 (3H, d)_:

0.83 (3H, d).

Monichydrazide A (Compound No 65 of Table 1)

"E NMR δ(d₄-MeOH) 5.80 (IH, s), 2.28 (3H, s), 1.30 (3H, d), 1.04 (3H, d).

N-(Prop-2-ylidiene)monichydrazone A (Compound No 83 of Table 1).

^XH NMR δ(d₄-MeOH) 6.84 (IH, s), 5.76 (IH, s), 2.33 (3H, s), 2.20 (3H, s),

2.12 (3H, s), 1.35 (3H, d), 1.10 (3H, d).

N-(2,5-Dichlorophenyl)monicamide A (Compound No 59 of Table 1) hi NMR δ(dg-DMSO) 9.42 (IH, s), 7.86 (IH, d), 7.46 (IH, d), 7.18 (IH, dd),

6.05 (IH, s), 2.21 (3H, s), 1.02 (3H, d), 0.80 (3H, d).

Monic acid A pyrrolidine amide (Compound No 84 of Table 1). NMR δ(CDCl₃) 5.88 (IH, s), 3.46 (4H, m), 2.08 (3H, s), 1.90 (4H, m),

1.21 (3H, d), 0.92 (3H, d). Monic acid A 2,6-dimethylmorpholine amide (Compound No 85 of Table 1).

¹H NMR δ(CDCl₃) 5.80 (IH, s), 3.50 (6H, m), 1.85 (3H, s), 1.20 (9H, ),

0.93 (3H, d).

N-Allylmonicamide A (Compound No 86 of Table 1).

~E NMR δ(CDCl₃) 5.92-5.72 (2H, m), 5.68 (IH, s), 5.22-5.10 (2H, m), 3.10

(2H, m), 2.18 (3H, s), 1.21 (3H, d), 0.92 (3H, d).

N,N-bis(2-hydroxyethyl)monicamide A (Compound No 87 of Table 1). ^λE NMR δ(d6-DMS0) 5.90 (IH, s), 3.40 (4H, m), 3.30 (4H, m), 1.80 (3H, s),

1.10 (3H, d), 0.78 (3H, d)

EXAMPLE 57

This Example illustrates the preparation of S-(carbomethoxymethyl) thiomonate A (Compound No 75 of Table I).

Monic acid A (80mg, 0.23mM) was dissolved in tetrahydrofuran (3ml) and cooled to -10°C under nitrogen. Triethylamine (24mg, 0.23mM) and a solution of isobutylchloroformate (32mg, 0.23mM) in tetrahydrofuran (0.7ml) were added and stirred for 20 minutes. A solution of methylthioglycolate (25mg, 0.23mM) in tetrahydrofuran (0.5 ml) was added an the reaction mixture stirred for 1 hour and then at room temperature for 3 hours. The reaction mixture was evaporated in vacuo and the resulting residue stored at room temperature for 7 days. The mixture was purified by column chromatography (silica gel, eluting with methanol/chloroform 1:9) to give the desired product as a colourless gum (67 mg, 67%). ^λE NMR δ(CDCl₃) 6.10 (IH, s), 4.76 (3H, s), 4.74 (2H, s), 2.21 (3H, s), 1.22 (3H, d), 0.93 (3H, d).

EXAMPLES 58 AND 59

The following compounds were prepared using the general method of Example 57:

S-Phenylthiomonate A (Compound No 74 of Table 1) NMR δ(CDCl₃) 7.42 (5H, s), 6.18 (IH, s), 2.20 (3H, s), 1.22 (3H, d),

0.92 (3H, d).

S-(2-Vinyloxyethyl)thiomonate A (Compound No 68 of Table 1)

~B NMR δ(CDCl₃) 6.45 (IH, dd), 6.07 (IH, s), 5.80 (2H, s), 3.18 (2H, t),

2.21 (3H, s), 1.73 (2H, t), 1.21 (3H, d), 0.95 (3H, d). EXAMPLE 60

This Example illustrates the preparation of 3-Nitrophenyl monate A (Compound No 52 of Table 1).

Monic acid A (200mg, 0.58mM) was dissolved in tetrahydrofuran (5.5ml) and cooled to -10°C under nitrogen. Triethylamine (59mg, 0.58mM) and isobutylchloroformate (80mg, 0.58mM) were added and stirred for 10 minutes and then at room temperature for 1 hour. Solids were removed by filtration and the filtrate concentrated in vacuo. The residue was taken up in dichloromethane (2.5ml) and 3-nitrophenol (323mg, 2.32mM) added. A solution ^"of pyridine (35mg) in dichloromethane (0.5ml) was added to give a clear homogeneous solution and the mixture was stirred at room temperature overnight. Solvents were removed in vacuo and separated on silica eluting with 55:45 acetone/hexane to give the desired product. NMR δ(CDCl₃) 8.10 (IH, d), 8.02 (IH, m), 7.54 (IH, t), 7.47 (IH, d), 6.02 (IH, s), 2.19 (3H, s), 1.22 (3H, d), 0.95 (3H, d).

EXAMPLES 61 TO 67

The following compounnds were preared using the general method of Example 60:

Phenyl monate A (Compound No 50 of Table 1)

-R NMR δ(CDCl₃) 7.39 (2H, t), 7.21 (IH, t), 7.10 (2H, d), 6.00 (IH, s),

2.28 (3H, s), 1.21 (3H, d), 0.93 (3H, d).

Furfuryl monate A (Compound No 56 of Table 1)

-E NMR δ(CDCl₃) 7.42 (IH, s), 6.41 (IH, d), 6.32 (IH, t), 5.79 (IH, s),

5.08 (2H, s), 2.22 (3H, s), 1.21 (3H, d), 0.94 (3H, d).

Neopentyl monate A (Compound No 38 of Table 1) NMR δ(CDCl₃) 5.78 (IH, s), 3.79 (2H, s), 2.21 (3H, s), 1.21 (3H, d),

0.95 (12H, m).

2-Chloroethyl monate A (Compound No 57 of Table 1) H NMR δ(CDCl₃) 5.81 (IH, s), 4.37 (2H, t), 3.72 (2H, t), 2.24 (3H, s),

1.22 (3H, d), 0.98 (3H, d).

4-Methoxyphenyl monate A (Compound No 53 of Table 1)

^■"^"H NMR δ(CDCl₃) 7.01 (2H, d), 6.88 (2H, d), 5.97 (IH, s), 3.80 (3H, s),

2.26 (3H, s), 1.22 (3H, d), 0.94 (3H, d). 4-Chlorophenyl monate A (Compound No 51 of Table 1)

~E NMR δ(CDCl₃) 7.28 (2H, d), 6.97 (2H, d), 5.91 (IH, s), 2.20 (3H, s),

1.15 (2H, d), 0.88 (2H, d).

2-(Vinylthio)ethyl monate A (Compound No 67 of Table 1)

-R NMR δ(CDCl₃) 6.33 (IH, dd), 5.78 (IH, s), 5.28 (IH, d), 5.20 (IH, d), 4.28 (2H, t), 2.95 (2H, t), 2.21 (3H, s), 1.21 (3H, d), 0.95 (3H, d).

EXAMPLE 68

The following Example illustrates the preparation of Monic acid A trimethylsulphonium salt (Compound No 88 of Table 1).

Trimethylsulphonium iodide (59mg, 0.29mM) was dissolved in water (5ml) and treated with Dowex 1X2 (H0~) resin for 10 minutes. The solution was filtered into a solution of monic acid A (lOOmg, 0.29 mM) in water (10ml). The solution was freeze-dried to give the desired product. ~E NMR δ(D₂0) 5.70 (IH, s), 2.83 (9H, s), 1.90 (IH, s), 1.16 (3H, d), 0.91 (3H, d).

EXAMPLE 69

The following Example illustrates the preparation of 4-(Me hoxycarbonyl)phenyl monate A (Compound No 54 of Table 1).

Monic acid A (250mg, 0.72mM) was dissolved in dichloromethane (3ml). A solution of triethylamine (74mg, 0.73mM) in dichloromethane (1ml) was added and the mixture stirred at room temperature for 5 minutes. The reaction mixture was cooled in an ice/water bath and a solution of isoprenylchloroformate (88mg, 0.73mM) in dichloromethane (1ml) added slowly and the mixture stirred with cooling for a further 10 minutes. 4-(Methoxycarbonyl)phenol (166mg, 1.09mM) and N,N-dimethylaminopyridine (9mg) were added and the mixture stirred for a further 2 hours with cooling. The crude reaction mixture was separated on silica eluting with 55:45 acetone/hexane to give the desired product. NMR δ(CDCl₃) 8.08 (2H, d), 7.18 (2H, d), 5.99 (IH, s), 3.91 (3H, s), 2.27 (3H, s), 1.21 (3H, d), 0.93 (3H, d).

EXAMPLE 70

The following Example illustrates the preparation of 2-Vinyloxyethyl pseudomonate A (Compound No 89 of Table 1).

Pseudomonic acid A (200mg, 0.40mM) was dissolved in acetone (2ml) and stirred with l-chloro-2vinyloxyethane (85mg, 0.60mM) and sodium iodide (132mg, 88mM). Potassium carbonate (83mg, 0.60mM) was added and the mixture stirred at room temperature for 2 hours and at reflux overnight. Volatile components were removed by evaporation in vacuo. The residue was taken up in dimethylformamide (1ml) and N,N-dimethylpropyleneurea (0.5ml) and heated at 80°C for 4 hours. Further portions of l-chloro-2-vinyloxyethane (85mg, 0.60mM) and sodium iodide (120mg) were added and heating continued for 8 hours. The reaction mixture was partitioned between water and diethylether and the organic layer was washed with water and brine and then dried over magnesium sulphate. Separation on silica eluting with 55:45 acetone/hexane gave the desired product as a gum. ^~E NMR δ(CDCl₃) 6.49 (IH, m), 5.76 (IH, s), 4.32 (2H, t), 4.20 (IH, dd), 4.08 (2H, t), 2.32 (2H, t), 2.20 (3H, s), 1.21 (3H, d), 0.95 (3H, d).

EXAMPLES 71 AND 72 The following compounds were prepared using the general method of Example 70:

Ethyl pseudomonate A (Compound No 90 of Table 1). ^λE NMR δ(CDCl₃) 5.79 (IH, s), 4.15 (2H, q), 4.11 (2H, t), 2.28 (2H, t),

2.21 (3H, s), 0.95 (3H, d).

2-Hydroxyethyl pseudomonate A (Compound No 91 of Table 1). -E NMR δ(CDCl₃) 5.78 (IH, s), 4.21 (2H, t), 4.08 (2H, t), 2.32 (2H, t), 2.21 (3H, s), 1.21 (3H, d), 0.95 (3H, d).

EXAMPLE 73

The following Example illustrates the preparation of N,N-Diethyl pseudomonicamide A (Compound No 92 of Table 1).

Pseudomonic acid A (200mg, 0.40mM) was dissolved in tetrahydrofuran (4ml) and cooled to -10°C under nitrogen. Triethylamine (41mg, 0.40mM) and isobutylchloroformate (55mg, 0.40mM) were added and stirred for 30 minutes. A solution of diethylamine (32mg, 0.40mM) in tetrahydrofuran (2ml) was added an the reaction mixture stirred for 30 minutes and then stood at room temperature overnight. The reaction mixture was filtered and evaporated in vacuo. The residue was taken up in water (10ml) and extracted with chloroform (3x10ml). The combined organic extracts were dried over magnesium sulphate and evaporated in vacuo. The resulting residue was purified by column chromatography (silica gel, eluting with acetone/hexane 55:45) to give the product as a colourless gum.

^Η NMR δ(CDCl₃) 5.78 (IH, s), 4.08 (2H, t), 3.31 (4H, q), 2.28 (2H, t), 2.21 (3H, s), 1.22 (6H, t), 0.95 (3H, d). EXAMPLE 74 This example illustrates the preparation of monic acid A isopropylamine salt (Compound No 96 of Table 1)

Monic acid A (50mg, 0.15mM) was dissolved in tetrahydrofuran (2ml) and was treated with isopropylamine (8.6mg, 0.15mM). After 20 minutes at room temperature, a precipitate formed which was collected by filtration to give the desired product.

¹H NMR δ(CDCl₃) 5.76 (IH, s), 2.21 (3H, s), 1.21 (3H, d), 1.10 (6H, d),

0.93 (3H, d).

EXAMPLES 75 AND 76 The following compounds were prepared using the general method of

Example 74:

Monic acid A triethylamine salt (Compound No 97 of Table 1) NMR δ(CDCl₃) 5.80 (IH, s), 2.88 (6H, q), 2.13 (3H, s), 1.20 (12H, m),

0.92 (3H, d).

Pseudomonic acid A triethylamine salt (Compound No 98 of Table 2)

-E NMR δ(CDCl₃) 5.78 (IH, s), 4.08 (2H, t), 3.00 (6H, q), 2.21 (3H, s),

1.25 (9H, t), 0.94 (3H, d).

EXAMPLE 77

This Example illustrates the preparation of Monic acid A sodium salt (Compound No 99 of Table 1)

Monic acid A (1.2g, 3.48mM) was suspended in water (35ml) and was treated with an aqueous 0.1M solution of sodium hydroxide (34.8ml, 3.48mM). The solution was freeze dried to give the desired product as a white solid. -R NMR δ(D_2Q) 5.69 (IH, s), 1.85 (IH, s), 1.15 (3H, d), 0.90 (3H, d).

EXAMPLE 78

This Example illustrates the preparation of 2-ethoxyethyl monate C (Compound No 108 of Table 3) from monic acid C (Compound No 107 of Table 3)

Monic acid C (1.62g, 0.49mM) was taken up in a mixture of dimethylformamide (1ml) and N,N-dimethylpropyleneurea (0.43ml). Potassium carbonate (0.102g, 0.74mM) was added and the reaction mixture stirred for 1 hour at 80-90°C. After cooling to room temperature, a solution of 2-chloroethylethylether (0.107g, 0.99mM) in dimethylformamide (0.5ml) was added and the mixture stirred at room temperature for 19 hours, at 90°C for 6 hours and then left to stand at room temperature overnight. Volatile components were removed in vacuo and the residue separated on silica, eluting with acetone/hexane (1:1) to give the desired product as a gum. -E NMR δ(CDCl₃) 5.81 (IH, s), 5.45 (2H, d), 4.25 (2H, t), 3.75 (2H, t)_; 2.22 (3H, s), 1.23 (3H, t), 1.17 (3H, d), 1.00 (3H, d).

EXAMPLES 79 TO 87 The following compounds were prepared using the general method of Example 20:-

2-(Hex-2-en-l-yl)ethyl monate A (Compound No 94 of Table 1)

~E NMR δ(CDCl₃) 5.80 (IH, s), 5.30-5.60 (2H, m), 4.22 (2H, t), 2.21

(3H, s), 1.21 (3H, d), 0.95 (6H, m).

Cyclopropylmethyl monate A (Compound No 93 of Table 1)

~E NMR δ(CDCl₃) 5.80 (IH, s), 3.92 (2H, d), 2.23 (3H, s), 1.23 (3H, d)

0.94 (3H, d), 0.57 (2H, m), 0.29 (2H, ).

(E/Z) 2-(Prop-l-en-l-yloxy)ethyl monate A (1:1) (Compound No 24 of Table 1) -E NMR δ(CDCl₃) 6.24 and 5.79 (IH, 2 x d), 5.80 (IH, s), 4.81 and 4.44 (IH, 2 x m),426 (2H, m), 2.23 (3H, s), 1.23 (3H, d), 0.95 (3H, d).

2-(Prop-2-yloxy)ethyl monate A (239075) (Compound No 100 of Table 1)

-E NMR δ(CDCl₃) 5.81 (IH, s), 4.22 (2H, m), 3.63 (2H, t), 2.22 (3H, s),

1.23 (3H, d), 1.18 (6H, d), 0.95 (3H, d).

2-Methoxyethyl monate A (Compound No 101 of Table 1)

-E NMR δ(CDCl₃) 5.83 (IH, s), 4.25 (2H, t), 3.60 (2H, t), 3.40 (3H, s),

2.22 (3H, s), 1.23 (3H, d), 0.95 (3H, d).

2-(Prop-l-yloxy)-ethyl monate A (Compound No 102 of Table 1), a mixture of diastereoisomers.

~E NMR δ(CDCl₃) 5.80 (IH, s), 4.23 (2H, t), 3.65 (2H, t), 2.21 (3H, s), 1.60 (2H, t), 1.21 (3H, d), 0.90 (6H, m).

2-Ethoxy-l-methylethyl monate A (Compound No 103 of Table 1)

^XH NMR δ(CDCl₃) 5.78 (IH, s), 5.09 (IH, m), 2.21 (3H, s), 1.20 (9H, m),

0.93 (3H, d). 2-Cyclopropyloxyethyl monate A (Compound No 104 of Table 1)

-B NMR δ(CDCl₃) 5.81 (IH, s), 4.21 (2H, t), 3.72 (2H, t), 2.21 (3H, s),

1.21 (3H, d), 0.95 (3H, d), 0.60 (2H, m), 0.50 (2H, m).

2-Ethoxy-2-methylethyl monate A (Compound No 105 of Table 1), a mixture of diastereoisomers.

^~E NMR δ(CDCl₃) 5.68 (IH, s), 4.02 (2H, t), 2.21 (3H, s), 1.15 (6H, ), 0.88 (6H, m).

EXAMPLE 88 The following compounds were prepared using the general method of Example 60.

A (5:2) mixture of i) 2-(hex-l-en-l-yloxy)ethyl monate A (Compound No 34 of Table 1)

-R NMR δ(CDCl₃) 5.91 (IH, d), 5.79 (IH, s), 4.38 (IH, q), 2.20 (2H, s),

1.21 (3H, d), 0.92 (3H, d). and ii) 2-(l-(vinyl)-but-l-yloxy)ethyl monate A (Compound No 95 of Table 1) hi NMR δ(CDCl₃) 5.79 (IH, s), 5.62 (IH, m), 5.20 (IH, d), 2.20 (2H, s),

1.21 (3H, d), 0.92 (3H, d).

EXAMPLES 89 AND 90 The following compounds were prepared using the general method of Example 38:

N-Methoxymonicamide A (Compound No 106 of Table 1)

-B NMR δ(dg-DMSO) 5.58 (IH, s), 3.70 (3H, s), 2.20 (3H, s), 1.21 (3H, d),

0.95 (3H, d).

N-Ethylmonicamide A (Compound No 62 of Table 1)

-B NMR δ(CDCl₃) 5.64 (IH, s), 5.54 (IH, t), 3.33 (2H, q), 2.18 (3H, s), 1.22 (3H, d), 1.17 (3H, t), 0.95 (3H, d).

EXAMPLE 91

This Example illustrates the herbicidal properties of compounds according to the invention.

The herbicidal activity of the compounds was tested as follows: Each chemical was formulated by dissolving it in an appropriate amount, dependent on the final spray volume, of a solvent/surfactant blend which comprised 78.2 gm/litre of Tween 20 and 21.8 gm/litre of Span 80 adjusted to 1 litre using methylcyclohexanone. Tween 20 is a Trade Mark for a surface-active agent comprising a condensate of 20 molar proportions of ethylene oxide with sorbitan laurate. Span 80 is a Trade Mark for a surface-active agent comprising sorbitan mono-laurate. If the chemical did

3 not dissolve, the volume was made up to 5cm with water, glass beads were added and this mixture was then shaken to effect dissolution or suspension of the chemical, after which the beads were removed. In all cases, the mixture was then diluted with water to the required spray volume. If sprayed independently, volumes of 25cm 3 and 30cm3 were required for pre-emergence and post-emergence tests respectively; if sprayed together,

3 45cm was required. The sprayed aqueous emulsion contained 4% of the initial solvent/surfactant mix and the test chemical at an appropriate concentration.

The spray compositions so prepared were sprayed onto young pot plants (post-emergence test) at a spray volume equivalent to 1000 litres per hectare for Compound Numbers 1 to 22 and 400 litres per hectare for Compound Numbers 23 to 94. Damage to plants was assessed 13 days after spraying by comparison with untreated plants, on a scale of 0 to 9 where 0 is 0% damage, 1 is 1-5% damage, 2 is 6-15% damage, 3 is 16-25% damage, 4 is 26-35% damage, 5 is 36-59% damage, 6 is 60-69% damage, 7 is 70-79% damage, 8 is 80-89% damage and 9 is 90-100% damage.

The designation "-" indicates that a compound was not tested against the indicated species.

The results of the tests are given in Table III below.

TABLE III

Compound Rate of Pre- or TEST PLANTS No Application Post- kg/ha Emergence

Application BV BN GM ZM OS TA PA CA GA AR BP EH IH AT XT AF AM AE SH SV DS EC CE

TABLE III (Continued)

Compound Rate of Pre- or TEST PLANTS No Application Post- kg/ha Emergence

Application BV BN GM ZM OS TA PA CA GA AR BP EH IH AT XT AF AM AE SH SV PS EC CE

TABLE III (continued)

Compound Rate of Pre- or TEST PLANTS

No Application Post- kg/ha Emergence Application BV BN GM ZM TA PA MI CA GA AR EH IH AT XT AF AM LR SH SV BP PD EC CE

TABLE III (continued)

Compound Rate of Pre- or TEST PLANTS No Application Post- kg/ha Emergence

Application BV BN GM ZM TA PA MI CA GA AR EH IH AT XT AF AM LR SH SV BP PD EC CE

* Mixture of compounds

TABLE III (continued)

Compound Rate of Pre- or TEST PLANTS No Application Post- kg/ha Emergence

TABLE III (continued)

Compound Rate of Pre- or TEST PLANTS No Application Post- kg/ha Emergence

Application BV BN GM ZM TA PA MI CA GA AR EH IH AT XT ΛF AM LR SH SV BP PD EC CE

TABLE IV

Abbreviations used for Test Plants

BV - Sugar beet

BN - Rape

GM - Soybean

ZM - Maize

OS - Rice

TA - Winter wheat

PA - Polygonum aviculare

CA - Chenopodium album

GA - Galium aparine

AR - Amaranthus retroflexus

BP - Bidens pilosa

EH - Euphorbia heterophylla

IH - Ipomoea hederacea (post-emergence)

AT - AbutiIon theophrasti

XT - Xanthium strumarium

AF - Avena fatua

AM - Alopecurus yosuroides

AE - Agropyron repens

SH - Sorghum halepense

SV - Setaria viridis -

DS - Digitaria sanguinalis

EC - Echinochloa crus-galli

CE - Cyperus esculentus

MI - Matricaria perforata

LR - Lolium rigidum

PD - Paniucum dicotomifirum

CHEMICAL FORMULAE

(IN DESCRIPTION)

CHEMICAL FORMULAE

(IN DESCRIPTION)

(III) ( IV)

CHEMICAL FORMULAE (IN DESCRIPTION)

CH,

(XI) CHEMICAL FORMULAE

(IN DESCRIPTION)

Claims

1. A herbicidal composition comprising a compound of the formula (I) or (IA) or (IB) in admixture with a herbicidally acceptable carrier or diluent:-

wherein Y represents

or or

and wherein R² is a group CO-XR³ wherein X is 0 or S and R³ is hydrogen or an agrochemically acceptable ester-forming radical; or

R² is a group -R⁴ wherein R⁴ is an optionally substituted aryl or heterocyclic group; or R² is a group CO-NR⁵R⁶ wherein R⁵ and R⁶ are the same or different and each represent an agrochemically acceptable amide-forming radical; stereoisomers of the compounds of formula (I),

(IA) and (IB) and salts of the compound of formula (I), (IA) and (IB) wherein R² is COXR³, X is 0 and R³ is hydrogen.

2. A composition as claimed in claim 1 wherein R² is a group CO-XR³ and X is oxygen.

3. A composition as claimed in claim 1 or claim 2 wherein R² is a group CO-XR³ and R³ is optionally substituted C₁ to C₂₀ alkyl, optionally substituted C₂ to C₂₀ alkenyl, optionally substituted C₂ to C₂₀ alkynyl, optionally substituted C₃ to C₇ cycloalkyl, optionally substituted aryl or optionally substituted heterocyclyl.

4. A composition as claimed in claim 3 wherein the optional substituents which may be present in optionally substituted alkyl, alkenyl or alkynyl groups R³ are C_3-7 cycloalkyl, C_1-10 alkoxy C_1-10 thioalkyl, C_2-8 alkenoxy, C_2-8 thioalkenyl, C_2-8 alkyneoxy, C_2-8 thioalkynyl, halogen, halo-C_1-10 alkoxy, halo-C_2-8alkeneoxy, halo-C_2-8alkynoxy, carboxy, C_1-6 alkoxycarbonyl, carbamoyl, optionally substituted aryl, optionally substituted heterocyclyl, hydroxy, cyano, nitro,

C_1-6alkanoyloxy, amino, mono- and di-(C_1-6)alkylamino;

and wherein the optional substituents which may be present in C_3-7 cycloalkyl groups, R³ include C_1-6alkyl, halo-C_1-6alkyl, C_1-10 alkoxy,

C_1-10 thioalkyl, C_2-8 alkenyl, C_2-8 alkeneoxy, C_2-8 thioalkenyl, C_2-8 alkynyl, C_2-8 alkyneoxy, C_2-8 thioalkynyl, halogen, carboxy, C_1-6 alkoxycarbonyl, carbamoyl, optionally substituted aryl, optionally substituted heterocyclyl, hydroxy, cyano, nitro, C_1-6alkanoyloxy, amino, mono- and di-(C_1-6)alkylamino;

and wherein the optional substituents which may be present in the aryl or heterocyclyl groups are independently selected from halogen, C_1-6alkyl, C_1-6alkoxy, C_1-6thioalkyl, halo(C_1-6)alkyl,

hydroxy(C_1-6)alkyl, halo(C_1-6)alkoxy, C_2-8 alkenyl, C_2-8 alkeneoxy,

C_2-8 thioalkenyl, C_2-8 alkynyl, C_2-8 alkyneoxy, C_2-8 thioalkynyl, hydroxy, cyano, nitro, amino, mono- and di- C_1-6 alkylamino, C_1-6 alkanesulphinyl, C_1-6 alkane sulphonyl, carboxy, C_1-6alkoxycarbonyl, and C_1-6alkoxycarbonyl(C_1-6)alkyl groups.

5. A composition as claimed in claim 3 or claim 4 wherein R³ is C₁ to C₁₀ alkyl group which may be unsubstituted or optionally substituted by hydroxy, halogen or cyano.

6. A composition as claimed in claim 3 or claim 4 wherein R³ is a C₂ to

C₁₀ alkenyl group which may be unsubstituted or optionally substituted by hydroxy, halogen or cyano.

7. A composition as claimed in claim 1 wherein R² is a group CO-XR³ and

R³ is a C_1-10 alkyl group substituted by a group -A-R¹¹ wherein A is 0 or a group S(0)_x wherein x is 0, 1 or 2 and R¹¹ is an optionally substituted C₁ to C₁₀ akyl group, an optionally substituted C₂ to C₈ alkenyl group, an optionally substitued C₂ to C₈ alkynyl group, an optionally substituted phenyl group, an optionally substituted C_1-6 alkyl carbonyl group, an optionally substituted C_3-7 cycloalkyl group or an optionally substitututed C_3-7 heterocyclic group.

8. A composition as claimed in claim 7 wherein R³ is a C_1-4 alkyl group substituted by a group -A-R¹¹ wherein A is 0 or S and R¹¹ is an optionally substituted C₁ to C₆ akyl group, an optionally substituted

C₂ to C₆ alkenyl group, an optionally substitued C₂ to C₆ alkynyl group, an optionally substituted phenyl group, an optionally

substituted C_1-6 alkyl carbonyl group, an optionally substituted C_3-6 cycloalkyl group or an optionally substituted aliphatic C_3-7 oxygen-containing heterocyclic group.

9. A composition as claimed in claim 1 wherein wherein R² is a group

CO-XR³ and R³ is the group -(CH₂)_n,-A-CH=CH-R¹² wherein n' is an integer from 1 to 4 A is 0 or a group S(0)_x wherein x is 0, 1 or 2 and R¹² is hydrogen or a C₁ to C₄ alkyl group.

10. A composition as claimed in claim 1 wherein R² is a heterocyclic group -R⁴ and R⁴ is a group of formula (II):

wherein R¹⁴ and R¹⁵, which may be the same or different, are

independently selected from hydrogen, optionally substituted phenyl, optionally substituted C₁ to C₂₀ alkyl, optionally substituted C₂ to

C₈ alkenyl, optionally substituted C₂ to C₈ alkynyl, optionally substituted heterocyclyl or C₃ to C₇ cycloalkyl, X is a divalent group, -Y'-C=C- and Y' is oxygen or sulphur.

11. A composition as claimed in claim 10 wherein R⁴ is an optionally

substituted oxazol-2-yl group.

12. A composition as claimed in claim 1 wherein R² is a group CO-XR³ and

R³ is a group -Z-CO-R⁸ wherein Z is a C₁ to C₁₂ alkylene group and R⁸ represents an optionally substitued C_1-10 alkyl group, an optionally substituted C_3-8 cycloalkyl group, an optionally substituted C_2-10 alkenyl group, an optionally substituted C_2-10 alkynyl group, an optionally substituted aryl group, an optionally substituted aralkyl group, an optionally substituted cycloalkylalkyl group or an

optionally substituted heterocyclyl group.

13. A composition as claimed in claim 1 wherein R² is a group CO-NR⁵R⁶ and wherein R⁵ and R⁶ are the same or different and may each independently be:

(a) hydrogen or

(b) an optionally substituted C_1-20 alkyl group, an optionally

substituted C_2-20 alkenyl group or an optionally substituted

C_2-20 alkynyl group or (c) optionally substituted C₃ to C₇ cycloalkyl or

(d) optionally substituted aryl or

(e) optionally substituted heterocyclyl; or

(f) R⁵ and R⁶ together with the nitrogen atom to which they are

attached represent an optionally substituted C_5-7 heterocyclic ring or

(g) R⁵ is hydrogen and R⁶ is a group -NR²²-R²³R²⁴ wherein R²² is hydrogen or C_1-6 alkyl are R²³ and R²⁴, which may be the same or different, may independently take any of the meanings given for R⁵ and R⁶ under (a), (b), (c), (d), (e) and (f) above or

(h) R⁶ is a group -NR²²-N=CR²³R²⁴ wherein R²², R²³ and R²⁴ have the meanings given previously or

(i) R⁵ is hydrogen and R⁶ is a group -CR²⁵R²⁶-CO-W or - NR²⁷-CO-W wherein W is optionally substituted phenyl or optionally substituted heterocyclyl, R²⁵, R²⁶ and R²⁷ are indendently hydrogen or optionally substitued C_1-6 alkyl groups.

14. A composition according to claim 13 wherein R⁵ is hydrogen or a C_1-4 alkyl group and R⁶ is a C_1-4 alkyl group, each of which alkyl groups may independently be optionally substituted by C_3-7 cycloalkyl, C_1-4 alkoxy, halogen, carboxy, C_1-6 alkoxycarbonyl, carbamyl, optionally substituted aryl, optionally substituted heterocyclyl, hydroxy, C_1-6 alkanoyloxy, amino, mono- or di-(C_1-6)alkylamino or wherein R⁵ and R⁶ together with the nitrogen atom to which they are attached represent an optionally substituted C_5-6 aliphatic heterocyclic ring.

15. A composition acording to claim 14 wherein R⁵ and R⁶ together with the nitrogen atom to which they are attached represent morpholinyl, piperidyl, piperazinyl, or pyrollidinyl, each of which may be optionally substituted by halogen or C_1-4 alkyl.

16. A compound of the formula (I) or (IA) or (IB) in claim 1 wherein R² is a group CO-XR³ X, is 0 or S and R³ is a C_1-10 alkyl group substituted by a group -A-R¹¹ wherein A is 0 or a group S(0)_x wherein x is 0, 1 or 2 and R¹¹ is an optionally substituted C₁ to C₁₀ alkyl group, an optionally substituted C₂ to C₈ alkenyl group, an optionally

substituted C₂ to C₈ alkynyl group, an optionally substituted phenyl group, an optionally substituted C_1-6 alkyl carbonyl group, an optionally substituted C_3-7 cycloalkyl group or an optionally substitututed C_3-7 heterocyclic group, provided that R³ is not a group -(CH₂)₂- when R¹¹ is ethyl.

17. A compound as claimed in claim 16 wherein R³ is a C_1-4 alkyl group substituted by a group -A-R¹¹ wherein A is 0 or a group S(0)_x wherein x is 0, 1 or 2 and R¹¹ is an optionally substituted C₁ to C₆ akyl group, an optionally substituted C₂ to C₆ alkenyl group, an optionally substitued C₂ to C₆ alkynyl group, an optionally substituted phenyl group , an optionally substituted C_1-6 alkyl carbonyl group, an optionally substituted C_3-6 cycloalkyl group or an optionally substituted aliphatic C_3-7 oxygen-containing heterocyclic group.

18. A compound as claimed in claim 17 wherein wherein R³ is the group

-(CH₂)_n,-A-CH=CH-R¹² wherein n' is an integer from 1 to 4 A is 0 or a group S(0)_x wherein x is 0, 1 or 2 and R¹² is hydrogen or a C₁ to C₄ alkyl group.

19. A compound of formula (VI):

wherein R² is selected from the group consisting of

-CO-O-CH₂CN

-CO-O-CH₂-(3-bromophenyl)

-CO-O-CH₂-(3-methylphenyl)

-CO-O-CH₂-(4-hydroxymethylphenyl)

-CO-O-(CH₂)₈-Br

-CO-O-(CH₂)₁₅CH,

-CO-O-(CH₂)₂-O-CH₂-CH=CH₂

-CO-O-(CH₂)₂-O-CH=CH₂-CH₃

-CO-O-(CH₂)₃-CH=CH₂

-CO-O-(CH₂)₂-O-phenyl

-CO-O-(CH₂)₂-O-(4-chlorophenyl)

-CO-O-(CH₂)₂-O-CO-CH₃

-CO-O-(CH₂)₂-O-CH₂-CO-OC₂H₅

-CO-O-(CH₂)₃-C≡CH

-CO-O-(CH₂)₄-O-CH=CH₂

-CO-O-(CH₂)₃-O-CH=CH₂

-CO-O-(CH₂)₂-O-CH=CH-(CH₂)₃-CH₃

-CO-O-CH-(CH₃)₂

-CO-O-CH₂-C(CH₃)₃

-CO-O-(cyclohexyl)

-CO-O-(CH₂)₂-O-(CH₂)₂-O-CH₃

-CO-O-(CH₂)₂-O-CH₂-C≡CH

-CO-O-(CH₂)₂-O-CH₂-CH=CHCl

-CO-O-CH(CH₃)-CO-O-C₂H₅

-CO-O-CH₂-CH=CHCl

-CO-O-CH(CH₃)-CH=CH₂

-CO-O-CH₂-CH=CHCH₃

-CO-O-(4-chlorophenyl)

-CO-O-(3-nitrophenyl)

-CO-O-(4-methoxyphenyl)

-CO-O-CH₂-(furan-2-yl)

-CO-O-CH₂-CH₂Cl

-CO-NH-(2,4-dichlorophenyl)

-CO-NH-(2,5-dichloropheny1)

-CO-N(CH₃)-(2,4-dichlorophenyl)

-CO-NH-C₂H₅ -CO-NH-CH₂-CO-OC₂H₅

-CO-O-(CH₂)₂-S-CH=CH₂

-CO-S-(CH₂)₂-O-CH=CH₂

-CO-O-CH₂-O-CH=CH₂

-CO-O-(CH₂)₉CH₃

-CO-O-CH₂-O-C₂H₅

-CO-NH-(CH₂)₂-OH

-CO-NH-(CH₂)₂-O-C₂H₅

-CO-N(-CH₂-CH=CH₂)₂

-CO-NH-N(CH₃)₂

-CO-NH-N=C(CH₃)₂

-CO-N(CH₂-CH₂-OH)₂

-CO-O- (CH₃)₃S⁺

-CO-O-CH₂-cyclopropyl

-CO-O-(CH₂)₂-O-CH₂-CH=CH-CH₂-CH₂-CH₃ -CO-O-(CH₂)₂-O-C(C₃H₇)-CH=CH₂

-CO-O-CH₂-CH₂-O-CH(CH₃)-CH₃

-CO-O-CH₂-CH₂-O-CH₃

-CO-O-CH₂-CH₂-O-CH₂-CH₂-CH₃

-CO-O-CH(CH₃)-CH₂-O-CH₂-CH₃

-CO-O-CH₂-CH₂-O-(cyclopropyl)

-CO-O-CH₂-CH(CH₃)-O-CH₂-CH₃

-CO-NH-OCH₃

20. A compound of formula (IB):

wherein R² is selected from the group consisting of

-CO-O-CH₂-CH₂-O-CH=CH₂

-CO-O-C₂H₅

-CO-O-(CH₂)2-OH

-CO-O-CH₂-CH₂-O-C₂H₅

21. A process of severely damaging or killing unwanted plants, which

comprises applying to the plants or to the growth medium of the plants a herbicidally effective amount of a compound of the formula (I) or (IA) or (IB) in claim 1 wherein R² is as defined in any of claims 1 to

15 or a herbicidally effective amount of a compound as claimed in any of claims 16 to 19.