WO1998032765A1

WO1998032765A1 - SULFAMATE DERIVATIVES WITH t-RNA SYNTHETASE INHIBITING ACTIVITY

Info

Publication number: WO1998032765A1
Application number: PCT/EP1998/000524
Authority: WO
Inventors: Desmond John Best; Neal Frederick Osborne; Donna Pengelly
Original assignee: Smithkline Beecham Plc
Priority date: 1997-01-27
Filing date: 1998-01-21
Publication date: 1998-07-30
Also published as: GB9701597D0

Abstract

Compounds of formula (I) in which: R1 is a pharmaceutically acceptable ester-forming radical; R2 is optionally substituted (C¿1-6?)alkyl; R?3¿ is hydrogen or optionally substituted (C¿1-6?)alkyl or aryl; and n is 1 or 2; are of use in inhibiting isoleucyl t-RNA synthetase.

Description

SULFAMATE DERIVATIVES WITH T-RNA SYNTHETASE INHIBITING ACTIVITY.

The present invention relates to novel anti-bacterial compounds, pharmaceutical compositions containing such compounds, processes for the preparation thereof and the use thereof in therapy.

Anti-bacterial agents operate via a series of different mechanisms which result in a bacteriocidal and/or bacteriostatic effect. One such mechanism which has been taken advantage of is selective inhibition of a bacterial aminoacyl t-RNA synthetase. t-RNA synthetases have a primary role in protein synthesis according to the following scheme:

Enzyme +ATP + AA o Enzyme. AA- AMP + PPi

Enzyme.AA-AMP + t-RNA <r> Enzyme + AMP + AA-t-RNA

in which AA is an amino acid.

Inhibition of this process leads to a reduction in the levels of charged t-RNA and this triggers a cascade of responses known as the stringent response, the result of which is the induction of a state of dormancy in the organism.

Mupirocin (orginally known as pseudomonic acid A), the compound of formula (A):

(A) is an antibacterial agent which inhibits protein synthesis through reversible selective inhibition of isoleucyl t-RNA synthetase by preventing formation of an He. AMP intermediate, from both Gram -positive and Gram-negative bacteria. It shows excellent selectivity for prokaryote over eukaryote isoleucyl t-RNA synthetases and also excellent selectivity for the isoleucyl t-RNA synthetase over the other nineteen bacterial aminoacyl t-RNA synthetases. The compound is marketed as a topical antibacterial product under the trade name Bactroban by SmithKline Beecham; ester lability precluding systemic administration.

The relative instability of mupirocin has limited the therapeutic use thereof to topical applications. Much effort has therefore been devoted to developing derivatives of mupirocin which retain the desirable antibacterial properties thereof but which are sufficiently stable to allow for systemic use. Attention has focussed on replacing the α,β-unsaturated ester moiety with a variety of other structural units which may be more resistant to enzymatic hydrolysis, for instance: α-methyl-α,β-unsaturated esters (EP 0 090 603-A); ,β-unsaturated thiol esters (EP 0 002 371-A); α,β-unsaturated amides (EP 0 001 914-A); α,β-unsaturated ketones (EP 0 029 665-A, WO 91/09855, WO 92/02518, J Med Chem, 1989, 32, 151); β-hydroxy ketones (WO 93/06118), cyclic ketones (WO 94/02478) and 5- and 6-membered heterocyclic rings (EP 0 087 953-N EP 0 123 378-A, EP 0 352 909-A, EP 0 399 645-A and WO 91/09856). In adition, related compounds have been described in which the C1-C3 moiety is replaced by a heterocyclic moiety (PCT application no. PCT/EP94/04136, SmithKline Beecham plc)

More recently, there have been reports of compounds produced by marine microrganisms which are closely related to mupirocin and which have antibacterial activity The compound of formula (D):

(D) in which R is hydrogen or hydroxyl is produced by an Alteromonas species associated with a marine sponge (Stierle D B and Stierle A A, 200th National Meeting of ACS, Washington DC, Aug 26-31, 1990 and Experientia, 1992, 48, 1165) The stereochemistry of the C-4 hydroxyl was inferred to be β-, based on spectroscopic studies.

In addition, further compounds, named thiomarinol and thiomarinol C are produced by the microorganism Alteromonas rava. These have the general formula (E):

(E) in which R is hydroxyl (thiomarinol) or hydrogen (thiomarinol C) [EP 0 512 824-A1, Sankyo Co Ltd and Shiozawa et al, J Antibiotics, 1993(12), 46, 1834-1842 (thiomarinol) and EP 0 595 458-A1, Sankyo Co Ltd (thiomarinol C)]. The thiomarinols are said to possess good anti-bacterial activity against both Gram-positive and Gram-negative organisms, as well as being active against mycoplasma. The amine forming the terminal amide is a pyrrothine, in particular a holothin. The acetamides thereof include the known anti-bacterial compounds thiolutin (Merck Index, 11th edn, 1989, 1471) and holomycin (Merck Index, 11th edn, 1989, 747). Thiolutin also has anti-fungal activity.

Semi-synthetic compounds related to thiomarinol in which the linkage between the monic acid and pyrrothine moieties is varied have recently been described (PCT applications, publication nos WO 94/26750; WO 94/28001 and WO 95/05384, SmithKline Beecham pic).

More recently, further modifications at the 5-position of the tetrahydropyranyl ring have been investigated, for instance International Application WO 97/05126 (SmithKline Beecham pic) describes compounds of the formula (A):

(A) in which:

R^a is an pharmaceutically acceptable ester-forming radical; R"³ is an optionally substituted (Cι _6)alkyl or (Cι_6)alkylamino group; Z is O or H,H; and n is 1 or 2; whilst International Application WO 97/35859 (SmithKline Beecham pic) describes similar compounds in which the carboxy ester is replaced by a range of other groups.

It has now been surprisingly found that further modifcation of the substituent R^ϋ enhances the whole cell activity of such sulfamoyl monate compounds.

Accordingly, the present invention provides for a compound of formula (I):

(I) in which: R! is an pharmaceutically acceptable ester-forming radical; R² is optionally substituted (Cι _6)alkyl; R^ is hydrogen or optionally substituted (Cι_6)alkyl or aryl; and n is 1 or 2.

Compounds of formula (I) are selective inhibitors of bacterial isoleucyl t-RNA synthetase and therefore potentially of use as anti-bacterial agents. Whole cell activity is enhanced by the incorporation of an aminoacid moiety CH(NH2)R^CO.

Suitable ester forming radicals R^ are well known in the art and include those previously described in GB 1 587 059 (Beecham Group Ltd), for instance: a) (Ci_2o)alkyl, (C2-8)^alkenyl ^or (C2-8) ^alkynyl ^eacn of which may be optionally substituted by (C3_7)cycloalkyl, halogen, carboxy, (C₁ _6)alkoxycarbonyl, carbamoyl, aryl, heterocyclyl, hydroxy, (Cι_6)alkanoyloxy, amino, mono- and di- (Cι _6)alkylamino; b) (C3_7)cycloalkyl optionally subsituted with (Cι _2)alkyl; c) aryl; and d) heterocyclyl.

Representative examples of R* include methyl, ethyl and (CH2)sCO2H and pharmaceutically acceptable salts and esters thereof.

Suitable values for R² include optionally substituted methyl, ethyl, propyl, 1 -methyl propyl and butyl.

Suitable substituents for R² include hydroxyl, carboxy, carbamoyl, amino, aryl, heterocyclyl, hydroxy, thio, (Cι _6)alkylthio and guanidino Suitable values of R^ include optionally substituted methyl, ethyl, propyl, butyl and phenyl.

Suitable substiuents for an alkyl or aryl group in R^ include amino, (C \ _6)alkylamino, di-(Cι _6)alkylamino, carboxy, hydroxy, thio, (Cι .g)alkylthio, guanidino and optionally substituted heterocyclyl and aryl, for instance optionally substituted phenyl and naphthyl.

Suitable values of the moiety R^CH(NH2)CO include those derived from naturally occurring L-amino acids such as phenylalanine, lysine, aspartic acid, tyrosine and tso-leucine.

Representative examples of the group R-* include benzyl, 4-aminobutyl, carboxymethyl, 4-hydroxyphenylmethyl, 2-naphthylmethyl, 1-methylpropyl and phenyl.

Suitably, n is 1.

Suitably, the moiety R²CH(NH)CO is derived from a naturally occurring amino acid, preferably iso-leucine. Accordingly, it will be readily appreciated that within compounds of formula (I), there is a subclass of compounds which may be represented by the formula (IA):

(IA) in which:

Rl, R3 and n are as hereinbefore defined and the absolute configuration of the chiral centres of the isoleucyl residue is S.

It will be further readily appreciated by those skilled in the art that compounds of the formula (1) are zwitterionic and may therefore be more accurately represented by a formula of the type (LB):

(LB)

Rl, R2, R3 and n are as hereinbefore defined.

When used herein, the term 'alkyl' and similar terms such as 'alkoxy' refers to, unless otherwise indicated, all straight and branched chainisomers. Representative examples thereof include, for instance, methyl, ethyl, «-propyl, tso-propyl, w-butyl, sec-butyl, tsø-butyl, t-butyl, n- pentyl and w-hexyl. Alkyl groups may be optionally substituted with one or two substituents selected from halogen, cyano, azido, nitro, carboxy, (Cι _6)alkoxycarbonyl, carbamoyl, mono- or di-(C \ _5)alkylcarbamoyl, sulpho, sulphamoyl, mono- or di-(Cι _6)alkylsulphamoyl, amino, mono- or di-(C i _6)alkylamino, acylamino, ureido, (Cι_6)alkoxycarbonylamino, 2,2,2-trichloroethoxycarbonylamino, aryl, heterocyclyl, hydroxy, (Cι_6)alkoxy, acyloxy, oxo, acyl, 2-thienoyl, thio, (Cι _6)alkylthio, (Cι _6)alkylsulphinyl, (Cι_ 5)alkylsulphonyl, hydroxyimino, (Cι_6)alkoxyimino, hydrazino, hydrazono, benzohydroximoyl, guanidino, amidino and iminoalkylamino.

When used herein, the term 'aryl' includes, unless otherwise defined, phenyl and napthyl optionally substituted with up to five substituents selected from halogen, C\_ ), (Ci _ g)alkoxy, halo(Cι_6)alkyl, hydroxy, amino, carboxy,

(Cι _6)alkoxycarbonyl or (Cι _6)alkoxycarbonyl(Cι_6)alkyl groups.

When used herein, the term 'heterocyclyl' includes, unless otherwise defined, single or fused rings comprising up to four hetero atoms in the ring selected from oxygen, nitrogen and sulphur and optionally substituted with up to three substituents selected from halogen, (Cι_6)alkyl, (C \ .g)alkoxy, halo(C \ _6)alkyl, hydroxy, amino, carboxy, (Cι _6)alkoxycarbonyl, (Cι _6)alkoxycarbonyl, (Cι _6)alkyl, aryl or oxo groups.

Since the compounds of formula (I) of the present invention are intended for use in pharmaceutical compositions, it will be understood that they are each provided in substantially pure form, for example at least 50% pure, more suitably at least 75% pure and preferably at least 95% pure (% are on a wt/wt basis). Impure preparations of the compounds of formula (I) may be used for preparing the more pure forms used in the pharmaceutical compositions. Although the purity of intermediate compounds of the present invention is less critical, it will be readily understood that the substantially pure form is preferred as for the compounds of formula (I). Preferably, whenever possible, the compounds of the present invention are obtained in crystalline form.

When some of the compounds of this invention are allowed to crystallise, or are recrystallised, from organic solvents, solvent of crystallisation may be present in the crystalline product. This invention includes within its scope such solvates. Similarly, some of the compounds of this invention may be crystallised or recrystallised from solvents containing water which may lead to the formation of hydrated products. This invention includes within its scope stoichiometric hydrates as well as compounds containing variable amounts of water that may be produced by processes such as lyophilisation.

Compounds of the present invention are active, in vitro, as selective inhibitors of isoleucyl t-RNA synthetases from a range of Gram-positive and Gram-negative organisms.

The compounds of this invention which have whole cell activity are active against both Gram negative and Gram positive organisms, including Bacteroides, for instance B. fragilis BC1, Haemophilus, for instance H. iηβuenzae Ql; Moraxella, for instance M. catarrhalis 1502; Streptococci, for instance S. pyogenes CN10 and S. pneumoniae PU7; Staphylococci, for instance S. aureus Oxford; Escherichia, for instance E. Coli DCO, Legionella, for instance L. pneumophila; Pseudomonas, for instance P. aeruginosa Dalgleish and Enterobacter, for instance Ent. faecelis I. In addition, compounds of this invention are active against Staphylococci organisms such as S. aureus and coagulase negative strains of Staphylocci such as S. epidermidis which are resistant (including multiply-resistant) to other anti-bacterial agents, for instance, β- lactam antibiotics such as, for example, methicillin; macrolides; aminoglycosides, and lincosamides. Compounds of the present invention are therefore useful in the treatment of MRSN MRCNS and MRSE. Furthermore, compounds of the present invention are useful in the treatment of Staphylococci organisms which are resistant to mupirocin. Bacterial infections which may be treated include respiratory tract infections, otitis, meningitis, skin and soft tissue infections in man, mastitis in cattle, and respiratory infections in animals such as pigs and cattle. Accordingly, in a further aspect, the present invention provides a method of treating bacterial infection in human or non-human animals, which method comprises administering a therapeutically effective amount of a compound of formula (I) as hereinbefore defined, to a human or non-human animal in need of such therapy.

The compounds of this invention are also active against mycoplasma-induced infections, in particular infections caused by Mycoplasma fermentans, which has been implicated as a co-factor in the pathogenesis of AIDS. Accordingly in a further aspect, the present invention provides a method of treating humans infected with fermentans, in particular humans also infected with HIV, which method comprises treating humans in need of such therapy with an anti-mycoplasmal effective amount of a compound of formula (I).

Compounds of this invention also have antifungal activity. They may, for example, be used in treating fungal infections in man caused by, among other organisms, species of Trichophyton, Trichosporon, Hendersonula, Microsporum, Epidermophyton, Candida, Cryptococcus, Saccharomyces, Paecilomyces and Pityrosporum. They may also be used in the treatment of a variety of other fungal infections caused by, for example Aspergillus, Coccidioides, Paracoccidioides, Histoplasma and Blastomyces species. Accordingly, in a further aspect, the present invention provides for a method of treating fungal infections in animals, including man, which method comprises treating a patient in need of antifungal therapy with an effect amount of a compound of formula (I).

Compounds of the present invention are also useful as herbicides and 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. Compounds for use in hebicidal compositions of the present invention are preferably applied directly to unwanted plants (post-emergence application) but may also be applied to the soil before the unwanted plants emerge (pre-emergence application). Therefore, in a further aspect, the present invention provides for a process of severely damaging or killing unwanted plants which process comprises applying to the plants or the growth medium of the plants a herbicidally effective amount of a compound of formula (I), as hereinbefore defined.

For herbicidal use, compounds of the present invention are preferably used in the form of a composition further comprising a carrier which may be a liquid or solid diluent. Suitable such compositions may be dilute compositions which are ready for immediate use or concentrated compositions which are diluted prior to use, usually with water. Suitable liquid compositions may comprise a solution or a dispersion of the active ingredient in water, optionally with a surfactant, or may comprise a solution or a dispersion of the active ingredient in a water-immiscible organic solvent which is dispersed as droplets in water. Suitable solid compositions may be in the form of granules or dusting powders or dispersible powders or grains, further comprisng a wetting agent to facilitate dispersion. Suitable herbicidal formulating agents are well known in the art; see, for instance, WO 93/19599 (Zeneca Ltd).

A suitable rate of application for herbicidal use will will depend upon the particular application but will usually be in the range 0.0001 to 20kg/hectare, preferably 0.001 to lOkg/hectare, more preferably 0.001 to 2kg/hectare.

Compounds of the present invention may be used alone or in admixture with other another herbicide which will preferably have a complementary herbicidal activity in the particular application. Suitable such complememtary herbicides are disclosed in WO 93/19599 (Zeneca Ltd).

No adverse toxicological effects are expected from the administration of a compound of formula (I).

This invention also provides a pharmaceutical or veterinary composition which comprises a compound of formula (I) (hereinafter referred to as the 'drug') together with a pharmaceutically or veterinarily acceptable carrier or excipient. The compositions may be formulated for administration by any route, and would depend on the disease being treated. The compositions may be in the form of, for instance, tablets, capsules, powders, granules, suppositories, lozenges and liquid or gel preparations, including oral, topical and sterile parenteral suspensions.

Tablets and capsules for oral administration may be in unit dose presentation form, and may contain conventional excipients such as -binding agents, for example syrup, acacia, gelatin, sorbitol, tragacanth, or polyvinyl-pyrollidone; fillers, for example lactose, sugar, maize-starch, calcium phosphate, sorbitol or glycine; tabletting lubricants, for example magnesium stearate, talc, polyethylene glycol or silica; disintegrants, for example potato starch, or acceptable wetting agents such as sodium lauryl sulphate. The tablets may be coated according to methods well known in normal pharmaceutical practice. Oral liquid preparations may be in the form of, for example, aqueous or oily suspensions, solutions, emulsions, syrups or elixirs, or may be presented as a dry product for reconstitution with water or other suitable vehicle before use. Such liquid preparations may contain conventional additives such as suspending agents, for example sorbitol, syrup, methyl cellulose, glucose syrup, gelatin, hydrogenated edible fats; emulsifying agents, for example lecithin, sorbitan monooleate, or acacia; non-aqueous vehicles (which may include edible oils), for example almond oil, fractionated coconut oil, oily esters, glycerine, propylene glycol, or ethyl alcohol; preservatives, for example methyl or propyl /?-hydroxybenzoate or sorbic acid, and if desired conventional flavouring or colouring agents.

For topical application to the skin the drug may be made up into a cream, lotion or ointment. Cream or ointment formulations that may be used for the drug are conventional formulations well known in the art, for example, as described in standard text books of pharmaceutics and cosmetics, such as Harry's Cosmeticology, 7th edn, ed Wilkinson and Moore, 1982, George Godwin, Harlow, England and the British Pharmacopoeia.

Suitable ointment formulations include those described in EP 0 095 897-A(Beecham Group pic), for pseudomonic acid A (mupirocin), and comprise a polyethylene glycol or a polyethylene glycol analogue or derivative, preferably polyethylene glycol 400 optionally admixed with polyethylene glycol 4000.

Suppositories will contain conventional suppository bases, e.g. cocoa-butters or other glyceride.

For parenteral administration, fluid unit dosage forms are prepared utilizing the drug and a sterile vehicle. The drug, depending on the vehicle and concentration used, can be suspended in the vehicle. Advantageously, adjuvants such as a local anaesthetic, preservative and buffering agents can be dissolved in the vehicle. To enhance the stability the composition can be frozen after filling into the vial and water removed under vacuum. The dry lypophilized powder is then sealed in the vial. The drug can be sterilised by exposure to ethylene oxide before suspending in the sterile vehicle. Advantageously, a surfactant or wetting agent is included in the composition to facilitate uniform distribution of the drug.

For topical application to the ear, the drug may be made up into a suspension in a suitable liquid carrier, such as water, glycerol, diluted ethanol, propylene glycol, polyethylene glycol or fixed oils. For topical application to the eye, the drug is formulated as a suspension in a suitable, sterile aqueous or non-aqueous vehicle. Additives, for instance buffers such as sodium metabisulphite or disodium edetate; preservatives including bactericidal and fungicidal agents, such as phenylmercuric acetate or nitrate, benzalkonium chloride or chlorhexidine, and thickening agents such as hypromellose may also be included. The dosage employed for compositions administered topically will, of course, depend on the size of the area being treated. For the ears and eyes each dose will typically be in the range from 10 to 100 mg of the drug.

Veterinary compositions for intramammary treatment of mammary disorders in animals, especially bovine mastitis, will generally contain a suspension of the drug in an oily vehicle.

The compositions may contain from 0.1% to 99% by weight, preferably from 10-60% by weight, of the drug, depending on the method of administration. Where the compositions are in unit dose form, each dosage unit will preferably contain from 50-500 mg, of the drug. The dosage as employed for adult human treatment (average weight about 70 kg) will preferably range from 100 mg to 3 g per day, for instance 250 mg to 2 g of the drug per day, depending on the route and frequency of administration. Alternatively, the drug may be administered as part of the total dietary intake of a non-human animal. In this case the amount of drug employed may be less than 1% by weight of the diet and in preferably no more than 0.5% by weight. The diet for animals may consist of normal foodstuffs to which the drug may be added or the drug may be included in a premix for admixture with the foodstuff. A suitable method of administration of the drug to animals is to add it to the non-human animal's drinking water. In this case a concentration of the drug in the drinking water of about 5-500 mg/ml, for example 5-200 mg/ml, is suitable.

Compounds of formula (I) may be readily prepared using procedures well known to those skilled in the art. Thus, compounds of formula (I) may be prepared by a process which comprises coupling a compound of formula (II):

(II) in which Rl, R2 and n are as hereinbefore defined; with an activated, N-protected derivative of an α-amino acid of the formula (III):

R3CH(NH₂)CO₂H (III) in which R-* is as hereinbefore defined and in which any optional substituents therein, such as amino or carboxy, may be suitably be protected; in the presence of a suitable base, and thereafter, removing the amino and any other protecting group(s).

Suitable coupling conditions are well known to those skilled in the art. For instance, coupling may be achieved using an N-hydroxysuccinimide ester of a suitably protected α-amino acid of formula (III), in a polar solvent such as dimethyl formamide or acetonitrile, in the presence of a base such as triethylamine. Alternative activated, N- protected derivatives of α-amino acids of the formula (III) include acyl imidazoles which may be prepared by treatment of a suitably N-protected α-amino acid of the formula (III) with l, l'-carbonyldiimidazole in an aprotic solvent such as tetrahydrofuran. Suitable protecting groups for the α-amino function are well known in the art (see for instance Protective Groups in Organic Synthesis, T.W. Greene, Wiley-Interscience, New York, 2nd ed, 1991) and include groups such as N-tert- butoxycarbonyl (BOC) which may be removed by conventional means, eg by treatment with trifluoroacetic acid.

Compounds of formula (II) may be obtained by coupling a sulfamate of formula (IV)

(IV) in which X^ and X² which may be the same or different is each a hydroxyl protecting group, and n and R^ are as hereinbefore defined; with an activated derivative of a carboxylic acid of the formula (V):

R²CH(NH₂)CO₂H (V) in which R² is as hereinbefore defined and the amine group is suitably protected, for instance by a BOC protecting group; in the presence of a suitable base, followed by the removal of the protecting group(s). Suitable activated derivatives of carboxylic acids are well known to those skilled in the art and include anhydrides, mixed anhydrides, acid chlorides, N-hydroxsuccinimide esters, and acyl imidazoles. Suitable bases include tertiary amines eg 1,8- diazabicyclo[5,4,0]undec-7-ene.

Suitably, X and X² together form an acetal protecting group. Suitable means for removing the acetal hydroxyl protecting group include acidic conditions such as those which are used to remove a BOC protecting group from nitrogen

Compounds of formula (IV) may be readily obtained by treating a compound of formula (VI):

(VI) in which n, Rl, χl and X² are as hereinbefore defined; with a hydroxyl activating agent, for instance hexabutyldistannnoxane (to form an intermediate tin ether), followed by a sulphamoylating agent, for instance sulphamoyl chloride (H2NSO2CI) under conditions analogous to those described by Castro-Pichel J. et al (Tetrahedron 1987, 43(2), 383-389).

Compounds of formula (VI) may be readily obtained from an ester of monic acid C according to the synthesis outlined in Scheme 1. Compounds of formula (VI) correspond to compounds of formula (X) (when n=2) and (XL) (when n=l).

Scheme 1

(VII)

i) Ozone ii) Me₂S

i) Et₃N (VIM) ii) TiPS Trifiate NaBH,

(IX) (X)

i) Ozone i) Ozone ii) Me₂S ii) NaBH₄

(XI) (XII)

in which Z , Z² and 7? which may be the same or different, is each hydrogen or a hydroxyl protecting group and R^ is as hereinbefore defined. Suitably Z¹ is silyl protecting group, for instance trimethyl silyl, whilst Z² and 7? together preferably form an acetal protecting group.

Compounds of formula (VII) are esters of monic acid C and may conveniently be prepared from monic acid A by first forming an ester, according to the procedures described in GB 1 587 059 (Beecham Ltd) and then converting the epoxide moiety of the intermediate ester into a double bond by using a suitable deoxygenating agent, according to the procedures described in WO 94/26750 (SmithKline Beecham pic) and references therein. Monic acid A itself may be readily obtained from pseudomonic acid A by carefully controlled hydrolysis, according to the procedure described in GB 1 587 058 (Beecham Ltd).

Intermediate aldehydes of the formula (VIII) may be prepared using the method described by Forrest et al in Tetrahedron, 1994, 50, 10739.

When used herein, the term 'hydroxyl-protecting group' refers to any such group known in the art which may be removed without disruption of the remainder of the molecule. Suitable hydroxyl-protecting groups are described in Protective Groups in Organic Synthesis, T.W. Greene, Wiley-Interscience, New York, 2nd ed, 1991. Their use in pseudomonic acid chemistry is described in earlier patent applications, for instance WO 94/26750 (SmithKline Beecham pic). It will be readily appreciated that the hydroxyls of glycol function of the tetrahydropyran ring may also be protected together, by a suitable protecting group. The term 'hydroxyl-protecting group' also refers to such protecting groups. Particularly suitable protecting groups include silyl groups and, for the the glycol function of the tetrahydropyran ring, ortho esters and ketals.

The invention will now be described by the following examples (nmr assignments have been made using the numbering system conventionally used for pseudomonic acid derivatives):

Example 1 {3R,4R-Dihydroxy-2S-[3(E)-ethoxycarbonyI-2-methyIprop-2-en-l- yl] tetrahydropyran-5R-yl} ethyl 2S-(2S-amino-l-oxo-3-phenylprop-l-yI)amino- 3S-methyl-l-oxopent-l-ylsulfamate a) Ethyl 4- {(3aS,4S,7S,7aR)-2,2-dimethyI-7-(2-oxoethyl)-3a,6,7,7a- tetrahydro-4H-l,3-dioxolo [4,5-c]pyran-4-yl}-3-methylbut-2(E)-enoate

A mixture of ethyl monate C (3 5g, 9 8mmoles), 2,2-dimethoxypropane (20ml, 0 16 moles), dry tetrahydrofuran (THF)(30ml) and p-toluenesulphonic acid (0 4g) was stirred for lh at 20°C Ethyl acetate (50ml) was added and the solution washed with saturated aqueous sodium hydrogen carbonate (30ml) and brine (30ml) The solution was dried over anhydrous magnesium sulphate and evaporated to give the crude acetonide (3 86g, quant)

To the crude acetonide (2 2g, 5 5mmoles) in dry THF (20ml), triethylamine (1 16ml, 8 2 mmoles) followed by chlorotrimethylsilane (1 05ml, mmoles) and 4- dimethylaminopyridine (20mg) was added The solution was stirred at 20°C for 2h, filtered and evaporated to dryness Hexane (40ml) was added and the solution washed with water (40ml), saturated aqueous hydrogen carbonate solution and brine It was dried and evaporated to give the crude 13-tπmethylsilyl protected olefin (2 5g, 95%) The protected olefin (2g, 4 2mmoles) was dissolved in dichloromethane (35ml)/ethanol (20ml) and ozonised at -70°C in 1 -2min intervals each time monitoring the reaction by tic until all the starting material had just disappeared Dimethyl sulphide (0 7ml) was added and the solution stirred for 2h at 20°C It was diluted with ethyl acetate, washed with water, dried over anhydrous magnesium sulphate and evaporated The crude product was purified by flash chromatography on silica gel eluting with hexane ethyl acetate 3 1 gave the title aldehyde (lg,72%) as a colourless oil, δ_H(CDCl₃) 1 27 (3H, t, J 6 9Hz, 2"-H), 1 35 (3H, s, CM?), 1 5 (3H, s, C e), 2 15- 2 25 (4H, m, 15-H₃ and 4-H), 2 58-2 79 (3H, m, 9-H₂ and 8-H), 3 46 (1H, dt, J3 and 9Hz, 5H), 3 59 (1H, d, J 12Hz, 16-H), 3 69 (1H, dd, J 5 and 9Hz, 6-H), 3 75 (1H, dd, J 3 and 12Hz, 16-H), 4 06 (1H, bs, 7-H), 4 16 (2H, q, J7, 1"-H), 9 81 (1H, s, CHO) b) Ethyl 4-{(3aS,4S,7S,7aR)-2,2-dimethyI-7-hydroxymethyI-3a,6,7,7a- tetrahydro-4H-l,3-dioxolo [4,5c] pyran-4-yl}-3-methyIbut-2(E)-enoate

To the aldehyde from Example la (0 6g, 1 8 mmoles) in toluene (10ml), triethylamine (0 37ml, 2 7 mmoles) was added at 5°C followed by triisopropylsilyl trifluoromethanesulfonate (0 55ml, 1 98mmαles) The resulting solution was stirred at room temperature for 2 hours The crude reaction mixture was placed directly onto a silica gel column and eluted with hexane and hexane ethyl acetate 9 1 to give the triisopropylsilylenol ether (0 6g, 67% yield) as an oil, mlz MR⁺ 483 The triisopropylsilylenol ether (0 21 g, 4 35 mmoles) was dissolved in dichloromethane (3 ml) and ethanol (2ml) and treated with ozone at -70°C in 15 second intervals each time monitoring the reaction by tic until the starting material had just disappeared It was then treated with sodium borohydride (20mg, 4 35 mmoles) and stirred at -70°C for 1 hour A further equivalent of sodium borohydride (20mg, 4 35 mmoles) was added and the reaction stirred at room temperature for 1 hour After this time acetic acid (0 1ml) was added, the reaction was diluted with ethyl acetate, washed with water and brine, dried over anhydrous magnesium sulfate and evaporated The crude product was purified by column chromatography on silica gel eluting with 4 1 hexane:ethyl acetate to give the title alcohol (44mg, 60%) as an oil; δ_H(CDCl₃) 1.29 (3H, t, J 7.11Hz, 2"-H₃), 1.39 (3H, s, CMe), 1.52 (3H, s, CMe), 2.1-2.2 (5H, m, 15- H₃, 4-H and 8-H), 2.5 (1H, d, J 13.7Hz, 4-H), 3.45 (1H, ddd, J 2.7Hz, 5-H), 3.75-3.9 (5H, m, 16-H₂, 9-H₂, 6-H), 4.15 (2H, q, J 7.1Hz, 1 "-H), 4.3 (1H, m, 7-H), 5.75 (1H, s,

c) Ethyl 4-{(3aS,4S,7R,7aR)-2,2-dimethyI-7-SulfamidylmethyI-3a,6,7,7a- tetrahydro-4H-l,3-dioxolo [4,5,c]pyran-4-yl}-3-methylbut-2(E)-enoate To the alcohol from Example lb (0.75g, 2.38 mmoles) in benzene (50ml), hexabutyldistannoxane (2.4ml, 4.77 mmoles) was added and the mixture heated to reflux in Dean and Stark apparatus for 2 hours. After this time it was cooled to 5°C and a solution of sulfamoyl chloride (1.09g, 9.54 mmoles) in dry dioxane (10ml) was added dropwise. The solution was stirred for 0.5hour before being evaporated. Hot hexane was added, the solid filtered off and treated with dilute methanolic ammonia. It was evaporated to dryness and purified by column chromatography on silica gel eluting with dichloromethane/methanol mixtures to give title compound (410mg, 43%); δ

_H(CDC1₃) 1.3 (3H, t, J 3.6Hz, 2"-H₃), 1.4 (3H, s, CMe), 1.5 (3H, s, CMe), 2.2 (4H, m, 4-H, 15-H₃), 2.5 (2H, m, 4-H, 8-H), 3.4 (1H, m, 5-H), 3.6-3.8 (3H, m, 16-H₂, 6-H), 4.2 (2H, q, J 7.2Hz, 1"-H), 4.29 (1H, m, 7-H), 4.3 (2H, m, 9-H₂), 4.8 (2H, s, NH₂), 5.73 (1H, s, 2-H). d) {3R,4R-Dihydroxy-2S-[3(E)-ethoxycarbonyl-2-methyIprop-2-en-l-yl] tetrahydropyran-5R-yl} ethyl (2S,3S)-2-amino-3-methyl-l-oxopent-l- ylsulfamate

A mixture of the sulfamate from Example lc (0.34g, 1.04 mmoles), N-Boc-L- isoleucine N-hydroxysuccinimide ester (0.41g, 1.0 mmoles) and 1,8-diazabicyclo [5.4.0] undec-7-ene (0.155ml, 1.04 mmoles) were stirred at room temperature for 2 hours in dry dimethylformamide (DMF)(5ml). The solvent was evaporated and the crude protected product purified by column chromatography on silica gel eluting with methanol/dichloromethane mixtures to give protected product (0.41g,.64%). The protected product (0.4 lg, 6.7mmoles) was treated with trifluoroacetic acid (TFA)(0.8ml) in dichloromethane (8ml) After 4 hours the solvent was removed and the title compound isolated by HP20SS column chromatography eluting with tetrahydrofuran/water mixtures (52mg, 11%); δ_H(D₂O) 0.96 (3H, t, J7.4Hz, 5'-H₃), 1.05 (3H, d, J 7Hz, 6'-H₃), 1.28 (4H, m, + t, J 7.1Hz, 4^*-H and 2"-H₃), 1.5 (1H, m, 4'-H), 2.06 (1H, m, 3'-H), 2.16 (3H, s, 15-H₃), 2.3 (1H, m, 8-H), 2.4 (1H, dd, J 15 and 10-Hz, 4-H), 2.67 (1H, m, 4-H), 3.58 (1H, dd, J 3.2 and 7.7Hz, 6-H), 3.7 (1H, dd, J4.1 and 12.3Hz, 16-H), 3.74 (1H, d, J 4.2Hz, 2'-H), 3.85 (1H, dd, J 3.5 and 12.3Hz, 16-H), 3.96 (1H, ddd, J 3.2, 7.7 and 10Hz, 5-H), 4.09 (1H, dd, J 3.3 and 5.0Hz, 7-H), 4.19 (2H, q, J 7.2Hz, 1"-H₂), 4.19 (1H, dd, J 6.4, 10.1Hz, 9-H), 4.25 (1H, dd J 7.1, 10.1Hz, 9-H), 5.82 (1H, s, 2-H); δ_c(D₂O) 11.9 (C-6'), 14.3 and 15.4 (C-2" and 5'), 18.9 (C-15), 25.0 (C-4'), 37.3 (C-3'), 41.5 (C-8), 42.2 (C-4), 60.9 (C- 2'), 61.8 and 63.1 (C-16 and -1), 67.3 (C-6 or C-7), 69.0 (C-9), 69.6 (C6 or C7), 75.4 (C-5), 118.0 (C-2), 158.7 (C-3), 169.6 (C-l), 175.8 (C-l'); uv (EtOH) A^_ax 210.5 nm ( ε_m 17,517), LR (KBr) 3450.8, 1714.8, 1698, 1643.1, 1297.4cm^"1. mlz (electrospray) MH⁺ 467 e) {3R,4R-Dihydroxy-2S-[3(E)-ethoxycarbonyl-2-methylprop-2-en-l-yI] tetrahydropyran-5R-yl}methyl 2S-(2S-t-butoxycarbonylamino-l-oxo-3- phenylprop-l-yI)amino-3S-methyl-l-oxopent-l-ylsulfamate

A mixture of the sulfamate from Example Id (55mg), N-t-BOC-L-phenylalanine N- hydroxysuccinimide ester (45mg) and dry DMF (1ml) was stirred at room temperature for 18 hours and evaporated. The residue was chromatographed on silica gel eluting with dichloromethane/methanol mixtures to give the title compound (20mg) mlz (electro spray) MH⁺ 614.2. f) {3R,4R-Dihydroxy-2S-[3(E)-ethoxycarbonyl-2-methylprop-2-en-l-yl] tetrahydropyran-5R-yl} methyl 2S-(2S-amino-l-oxo-3-phenylprop-l-yI)amino-3S- methyl-l-oxopent-l-ylsulfamate

The product from Example le (20mg) was dissolved in TFA (1ml) and kept at room temperature for 10 minutes. The mixture was evaporated, re-evaporated from toluene, and the residue chromatographed on HP20SS eluting with THF/water mixtures. The appropriate fractions were evaporated and freeze dried to give the title compound as a solid (14mg); δ_H(D₂O) inter alia

0.85-0.94 (6H, m, 5'-H₃, 6'-H₃), 1.15-1.25 (1H, m, 4'-H), 1.26 (3H, t, J 7.2Hz, ester CH₃), 1.39-1.55 (1H, m, 4'-H), 1.6-1.74 (1H, m, 3'-H), 2.11 (3H, s, 15-H₃), 2.57 (1H, br. d, J 14.0Hz, 4-H), 3.52 (1H, dd, J7.6 and 3.1Hz, 6-H), 3.64 (1H, dd, J 12.3 and 3.7Hz, 16-H), 3.81 (1H, dd, J 12.3 and 3.8Hz, 16-H), 5.74 (1H, s, 2-H), 7.25-7.45 (5H, m, Ar-H). mlz (electrospray) MH⁺ 714, M+NH₄ ⁺ 731.

Example 2 {3R,4R-Dihydroxy-2S-[3(E)-ethoxycarbonyI-2-methylprop-2-en-l- yl] tetrahydropyran-5R-yl}methyl 2S-(2S-amino-6-amino-l-oxohex-l-yl)amino- 3S-methyl-l-oxopent-l-ylsulfamate a) {3R,4R-Dihydroxy-2S-[3(E)-ethoxycarbonyl-2-methylprop-2-en-l-yl] tetrahydropyran-5R-yl}methyl 2S-(6-amino-2S-t-butoxycarbonylamino-l- oxohex-l-yl)amino-3S-methyl-l-oxopent-l-yIsulfamate

A mixture of the sulfamate from Example Id (58mg), N,N-di-t-BOC-L-lysine N- hydroxysuccinimide ester (71mg), triethylamine (0.02ml) and dry DMF (1ml) was stirred at room temperature for 1 hour and worked up as in Example 1 e to give the title compound (61mg); mlz (electrospray) M+NH4⁺ 812. b) {3R,4R-Dihydroxy-2S-[3(E)-ethoxycarbonyl-2-methylprop-2-en-l-yl] tetrahydropyran-5R-yl} ethyl 2S-(2S-amino-6-amino-l-oxohex-l-yl)amino-3S- methyl-1-oxopent-l-ylsulfamate

The product from Example 2a (60mg) was dissolved in TFA (2ml) and kept at room temperature for 20 minutes. The mixture was worked up as for Example If to give the title compound as a solid (25mg); δ_H(D₂O) inter alia 0.84-0.97 (6H, m, 5'-H₃,6'-H ), 1.27 (3H, t, J 7Hz, ester CH₃), 1.58-1.71 (1H, m, 3'-H), 2.13 (3H, s, 15-H₃), 2.63 (1H, br. d, J 14Hz, 4-H), 2.98 (2H, t, J7Hz, 6"-H₂), 3.64 (1H, dd, J 13 and 3Hz, 16- H), 3.82 (1H, dd, J 13 and 3Hz, 16-H), 5.80 (1H, s, 2-H). mlz (electrospray) MH⁺ 595. Example 3 {3R,4R-Dihydroxy-2S-[3(E)-ethoxycarbonyl-2-methylprop-2-en-l- yl] tetrahydropyran-5R-yl} methyl 2S-(2S-amino-3-carboxy-l-oxoprop-l- yl)amino-3S-methyl-l-oxopent-l-ylsulfamate

The sulfamate from Example Id (56mg) was dissolved in dry DMF (1ml) and treated with N-t-BOC-β-t-butyl-L-aspartic acid N-hydroxysuccinimide ester (46mg) and triethylamine (0.02ml). After stirring at room temperature for 1 hour the mixture was worked up and deprotected using the methods described in Examples le and If to give the title compound as a solid (20mg); δ_H(D₂O) inter alia 0.80-0.99 (6H, m, 5'-H₃, 6'- H₃), 1.36-1.52 (IH, m, 4'-H), 1.80-1.94 (IH, m, 3'-H), 2.11 (3H, s, 15-H₃), 2.65 (IH, dd, J 17.5 and 9.3Hz, 3"-H), 2.88 (IH, dd, J17.5 and 4.7Hz, 3"-H), 3.55 (IH, dd, J7.6 and 3.1Hz, 6-H), 3.63 (IH, dd, J 12.2 and 3.8Hz, 16-H), 3.80 (IH, dd, J 12.2 and 3.2Hz, 16-H), 4.28 (IH, dd, J 9.3 and 4.7Hz, 2"-H), 5.78 (IH, s, 2-H). mlz (electrospray) MH⁺ 582.2.

Example 4 {3R,4R-Dihydroxy-2S-[3(E)-ethoxycarbonyI-2-methylprop-2-en-l- yl] tetrahydropyran-5R-yl} methyl 2S-[2S-amino-3-(4-hydroxyphenyl)-l- oxoprop-l-ylJamino-3S-methyI-l-oxopent-l-y.suIfan.ate a) {3R,4R-Dihydroxy-2S-[3(E)-ethoxycarbonyl-2-methylprop-2-en-l-yl] tetrahydropyran-5R-yl} methyl 2S-[2S-t-butoxycarbonylamino-3-(4- hydroxyphenyl)-l-oxoprop-l-yl]amino-3S-methyl-l-oxopent-l-ylsulfamate A mixture of the sulfamate from Example Id (47mg), N-t-BOC-L-tyrosine N- hydroxysuccinimide ester (45mg), triethylamine (0.017ml) and dry acetonitrile was stirred at room temperature for 1.5 hours and evaporated. The residue was chromatographed on silica gel eluting with dichloromethane/methanol mixtures to give the triethylamine salt of the title compound as a solid (46mg); δ_H(CD₃OD) inter alia 0.88-1.00 (6H, m, 5'-H₃, 6'-H₃), 1.37 (9H, s, CMe₃), 1.49-1.68 (IH, m, 4'-H), 1.85- 2.00 (IH, m, 3'-H), 2.16 (3H, s, 15-H₃), 2.58-2.79 (3H, m, 4-H, 3"-H), 3.08 (IH, dd, J 14.1 and 4.4Hz, 3"-H), 3.21 (2H, q, J7.3Hz, Et₃N-H₂), 3.35 (IH, dd, J 8.5 and 3.1Hz, 6-H), 3.59 (IH, br.d, J 10.6Hz, 16-H), 3.80 (IH, dd, J 12.0 and 2.9Hz, 16-H), 4.27 (IH, dd, J 9.9 and 4.4Hz, 2"-H), 5.72 (IH, s, 2-H), 6.69 and 7.07 (4H, each d, J 8.4Hz, Ar-H). mlz (electrospray) M+NH₄ ⁺ 747.3. b) {3R,4R-Dihydroxy-2S-[3(E)-ethoxycarbonyl-2-methylprop-2-en-l-yl] tetrahydropyran-5R-yl} methyl 2S-[2S-amino-3-(4-hydroxyphenyl)-l-oxoprop-l- yl]amino-3S-methyI-l-oxopent-l-ylsulfamate A solution of the product from Example 4a (44mg) in TFA (0.5ml) was kept at room temperature for 2.5 hours and evaporated. The residue was re-evaporated from toluene (2x1 ml) and chromatographed on silica gel eluting with dichloromethane/methanol mixtures to give the title compound as a solid (26mg); δ _H(D₂O) inter alia 0.81-0.96 (6H, m, 5'-H , 6'-H₃), 1.00-1.70 (IH, m, 4^*-H), 1.31-1.50 (IH, m, 4'-H), 1.74-1.93 (IH, m, 3'-H), 2.11 (3H, s, 15-H₃), 2.57 (IH, br.d, J 16.2Hz, 4-H), 2.89-3.11 (2H, m, 3"-H₂), 3.51 (IH, dd, J 7.6 and 3.1Hz, 6-H), 3.62 (IH, dd, J 12.3 and 3.8Hz, 16-H), 3.81 (IH, dd, J 12.3 and 3.3Hz, 16-H), 5.73 (IH, s, 2-H), 6.85 and 7.13 (4H, each d, J 8.5Hz, Ar-H). mlz (electrospray) MH⁺ 630.2. Example 5 {3R,4R-Dihydroxy-2S-[3(E)-ethoxycarbonyl-2-methylprop-2-en-l- yl] tetrahydropyran-5R-yl} methyl 2S-[2S-amino-3-(2-naphthyI)-l-oxoprop-l- yl]amino-3S-methyl-l-oxopent-l-yIsulfamate a) {3R,4R-Dihydroxy-2S-[3(E)-ethoxycarbonyl-2-methylprop-2-en-l-yl] tetrahydropyran-5R-yl} methyl 2S-[2S-t-butoxycarbonylamino-3-(2-naphthyI)-l- oxoprop-l-yI]amino-3S-methyl-l-oxopent-l-ylsulfamate A mixture of N-t-BOC-L-3-(2-naphthyl)alanine (38mg), 1 , l'-carbonyldiimidazole (24mg) and dry THF (1ml) was heated at 50°C under dry argon for 40 minutes. The mixture was cooled to room temperature and treated with the sulfamate from Example Id (47mg). After 2 hours at room temperature the mixture was diluted with ethyl acetate (5ml) and washed with 5% citric acid (2xlml) and brine (2xlml). The dried (MgSO4) organic layer was evaporated and the residue chromatographed on silica gel eluting with dichloromethane/methanol mixtures to give the title compound as a solid (19mg); δ_H(CD₃OD) inter alia 0.89-1.02 (6H, m, 5'-H₃, 6'-H₃), 1.50-1.70 (IH, m, 4'-H), 1.88-2.04 (IH, m, 3'-H), 2.15 (3H, s, 15-H₃), 2.61 (IH, br.d, J 14.3Hz, 4-H), 2.88-3.11 (2H, m, 3"-H₂), 3.59 (IH, br.d, J 11.7Hz, 16-H), 4.48 (IH, dd, J 10.3 and 4.2Hz, 2"-H), 5.70 (IH, s, 2-H), 7.36-7.50 (3H, m, Ar-H), 7.66-7.84 (4H, m, Ar- H). mlz (electrospray) M+NH4⁺ 781.3. b) {3R,4R-Dihydroxy-2S-[3(E)-ethoxycarbonyl-2-methylprop-2-en-l-yl] tetrahydropyran-5R-yl}methyl 2S-[2S-amino-3-(2-naphthyl)-l-oxoprop-l- yI]amino-3S-methyl-l-oxopent-l-ylsulfamate

The product from Example 5a (18mg) was treated with TFA (1.5 hours) and worked up as for Example 4b to give the trifluoroacetic acid salt of the title compound as a solid (15mg); δ_H(CD₃OD) inter alia 0.82-0.92 (6H, m, 5'-H₃, 6'-H₃), 1.03-1.18 (IH, m, 4'-H), 1.23 (3H, t, J7.2Hz, ester-CH₂), 1.40-1.60 (IH, m, 4'-H), 1.83-2.00 (IH, m, 3'-H), 2.60 (IH, br.d, J 13.9Hz, 4-H), 2.94-3.17 (2H, m, 3"-H₂), 3.58 (IH, br.d, J 11.7Hz, 16-H), 5.69 (IH, s, 2-H), 7.39-7.51 (3H, m, Ar-H), 7.72-7.88 (4H, m, Ar-H). mlz (electrospray) MH⁺ 664.2.

Example 6 {3R,4R-Dihydroxy-2S-[3(E)-ethoxycarbonyl-2-methylprop-2-en-l- yl] tetrahydropyran-5R-yl}methyl 2S-[2-amino-l-oxo-2-phenylethyl]amino-3S- methyl-1-oxopent-l-ylsulfamate

Using the methods described in Example 5, the sulfamate from Example Id (94mg) was coupled with the imidazolide prepared from N-t-BOC-L-phenylglycine (60mg) and the product was deprotected to give the title compound, a 3 :2 mixture of diastereomers, as a solid (23mg); δ_H(CD₃OD) wter alia 0.74-1.02 (6H, m, 5'-H , 6'- H₃), 1.25 (3H, t, J7.1Hz, ester-CH₂), 1.80-2.15 (IH, m, 3'-H), 2.63 (IH, br.d, J 14.1Hz, 4-H), 4.68 (0.6H, s, 2"-H), 4.74 (0.4H, s, 2"-H), 5.72 (IH, s, 2-H), 7.28-7.55 (5H, m, Ar-H). mlz (electrospray) MH⁺ 600.2.

Example 7 {3R,4R-Dihydroxy-2S-[3(E)-ethoxycarbonyl-2-methylprop-2-en-l- yl] tetrahydropyran-5R-yl}methyl 2S-[2S-amino-3S-methyl-l-oxopent-l- yl]amino-3S-methyl-l-oxopent-l-ylsulfamate

Using the methods described in Example 5, the sulfamate from Example Id (69mg) was coupled with the imidazolide prepared from N-t-BOC-L-isoleucine (41mg) and the product was deprotected to give the title compound as a solid (23mg); δ _H(CD₃OD) inter alia 0.89-1.00 (12H, m, 5'-H₃, 6'-H₃, 5"-H₃, 6"-H₃), 1.7-2.0 (2H, m, 3'-H, 3"-H), 2.64 (IH, br.d, J 14.1Hz, 4-H),3.60 (IH, br.d, J 11.7Hz, 6-H), 3.97-4.03 (IH, m, 7-H), 5.71 (IH, s, 2-H). mlz (electrospray) MH⁺ 580.

Claims

1. A compound of formula (I):

(I) in which:

R! is an pharmaceutically acceptable ester-forming radical;

R2 is optionally substituted (C╬╣_6)alkyl;

R^ is hydrogen or optionally substituted (C╬╣ _6)alkyl or aryl; and n is 1 or 2.

2. A compound as claimed in claim 1 in which R* is selected from: a) (C╬╣_2╬╕)^aM^{ l (C2-8)^alkenyl or (C2_s) alkynyl each of which may be optionally substituted by (C₃_7)cycloalkyl, halogen, carboxy, (C╬╣_6)alkoxycarbonyl, carbamoyl, aryl, heterocyclyl, hydroxy, (C╬╣ _6)alkanoyloxy, amino, mono- and di- (C╬╣ _6)alkylamino; b) (C₃_7)cycloalkyl optionally subsituted with (Ci _2)alkyl; c) aryl; and d) heterocyclyl.

3. A compound as claimed in claim 1 or 2 in which R! is methyl, ethyl or (CH2)gC╬╕2H or a pharmaceutically acceptable salt or ester thereof.

4. A compound as claimed in any one of claims 1 to 3 in which R^CH(NH)CO is derived from a naturally occurring amino acid.

5. A compound as claimed in claim 4 in which R^CH(NH)CO is derived L-iso-leucine.

6. A compound as claimed in any one of the preceding claims and represented by the (IA):

(IA) in which:

7. A compound as claimed in any one of claims 1 to 6 in which R^ is optionally substituted methyl, ethyl, propyl, butyl or phenyl.

8. A compound as claimed in claim 7 in which R^ is selected from benzyl,.4- aminobutyl, carboxymethyl, 4-hydroxyphenylmethyl, 2-naphthylmethyl, 1-methylpropyl and phenyl.

9. A compound as claimed in any one of claims 1 to 8 in which n is 1.

10. A compound of formula (I) selected from:

{ 3R,4R-Dihydroxy-2S-[3 (E)-ethoxycarbonyl-2-methylprop-2-en- 1 -yl] tetrahydropyran-5R-yl}methyl 2S-(2S-amino-l-oxo-3-phenylprop-l-yl)amino-3S- methyl- 1 -oxopent- 1 -ylsulfamate;

(3R,4R-Dihydroxy-2S-[3(E)-ethoxycarbonyl-2-methylprop-2-en-l-yl] tetrahydropyran-5R-yl} methyl 2S-(2S-amino-6-amino- 1 -oxohex- 1 -yl)amino-3 S- methyl- 1 -oxopent- 1 -ylsulfamate;

{3R,4R-Dihydroxy-2S-[3(E)-ethoxycarbonyl-2-methylpro╧ü-2-en-l-yl] tetrahydropyran-5R-yl } methyl 2S-(2S-amino-3 -carboxy- 1 -oxoprop- 1 -yl)amino-3 S- methyl- 1 -oxopent- 1 -ylsulfamate;

{3R,4R-Dihydroxy-2S-[3 (E)-ethoxycarbonyl-2-methylpro╧ü-2-en- 1 -yl] tetrahydropyran- 5R-yl}methyl 2S-[2S-amino-3-(4-hydroxyphenyl)-l-oxoprop-l- yl]amino-3 S-methyl- 1 -oxopent- 1 -ylsulfamate; {3R,4R-Dihydroxy-2S-[3(E)-ethoxycarbonyl-2-methylprop-2-en-l-yl] tetrahydropyran-5R-yl} methyl 2S-[2S-amino-3-(2-naphthyl)-l-oxoprop-l-yl]amino-

3 S-methyl- 1 -oxopent- 1 -ylsulfamate;

{3R,4R-Dihydroxy-2S-[3(E)-ethoxycarbonyl-2-methylprop-2-en-l-yl] tetrahydropyran-5R-yl} methyl 2S-[2-amino- 1 -oxo-2-phenylethyl]amino-3 S-methyl- 1 - oxopent- 1 -ylsulfamate; and

{ 3R,4R-Dihydroxy-2S-[3 (E)-ethoxycarbonyl-2-methylprop-2-en- 1 -yl] tetrahydropyran-5R-yl} methyl 2S-[2S-amino-3 S-methyl- 1 -oxopent- 1 -yl]amino-3 S- methyl- 1 -oxopent- 1 -ylsulfamate.

11. A pharmaceutical composition comprising a compound of formula (I) as defined in claim 1 and a pharmaceutically acceptable recipient or carrier.

12. A compound of formula (I) as defined for use in therapy.

13. A process for preparing a compound of formula (I) as defined in claim 1 which process comprises

(II) in which R , R^ and n are as defined in claim 1; with an activited, N-protected activated derivative of an ╬▒-amino acid of the formula (III): R³CH(NH₂)CO₂H

(HI) in which R^ is as hereinbefore defined and in which any optional substituents therein, such as amino or carboxy, may be suitably be protected; in the presence of a suitable base, and thereafter, removing the amino and any other protecting protecting group(s).