Abstract: The present teachings relate to pyrone derivatives, pharmaceutical compositions thereof, and methods of using such compounds to treat bacterial infections.

Abstract: A method for manufacturing a fatty acid derivative represented by formula (I) is provided: wherein Z1 is wherein R3 is a protecting group for a hydroxy group; which includes the step of reacting a compound of formula (II): wherein Z2 is the same as Z1 except for when Z1 is Z2 is with a co-oxidizer under the presence of an azaadamantane-N-oxyl derivative.

Abstract: The present invention relates to a compound of formula (I) for its use for reversing or inhibiting multidrug resistance.

Abstract: Disclosed is a method for preparing a prostaglandin derivative of formula (A): which comprises reacting an aldehyde represented by formula (1): with a 2-oxoalkyl phosphonate in a reaction solvent under the presence of alkali hydroxide as sole base. By carrying out the reaction using an alkali hydroxide as sole base in the reaction system, the desired prostaglandin derivative can be obtained by simple procedures and with high yield.

Abstract: The invention relates to the use of compounds to treat a number of conditions, such as thrombocytopenia, neutropenia or the delayed effects of radiation therapy. Compounds that can be used in the invention include methyl-2,3,4-trihydroxy-1-O-(7,17-dioxoandrost-5-ene-3?-yl)-?-D-glucopyranosiduronate, 16?,3?-dihydroxy-5?-androstan-17-one or 3,7,16,17-tetrahydroxyandrost-5-ene, 3,7,16,17-tetrahydroxyandrost-4-ene, 3,7,16,17-tetrahydroxyandrost-1-ene or 3,7,16,17-tetrahydroxyandrostane that can be used in the treatment method.

Abstract: There is provided processes for preparing Lubiprostone and intermediates thereof. Also provided are compounds, including intermediates for preparing Lubiprostone as well compositions comprising Lubiprostone and other compounds, including intermediates for preparing Lubiprostone and other compounds.

Abstract: The invention relates to the use of compounds to treat a number of conditions, such as thrombocytopenia, neutropenia or the delayed effects of radiation therapy. Compounds that can be used in the invention include methyl-2,3,4-trihydroxy-1-O-(7,17-dioxoandrost-5-ene-3?-yl)-?-D-glucopyranosiduronate, 16?,3?-dihydroxy-5?-androstan-17-one or 3,7,16,17-tetrahydroxyandrost-5-ene, 3,7,16,17-tetrahydroxyandrost-4-ene, 3,7,16,17-tetrahydroxyandrost-1-ene or 3,7,16,17-tetrahydroxyandrostane that can be used in the treatment method.

Abstract: Disclosed is a method for preparing a prostaglandin derivative of formula (A): which comprises reacting an aldehyde represented by formula (1): with a 2-oxoalkyl phosphonate in a reaction solvent under the presence of alkali hydroxide as sole base. By carrying out the reaction using an alkali hydroxide as sole base in the reaction system, the desired prostaglandin derivative can be obtained by simple procedures and with high yield.

Abstract: Disclosed is a method for preparing a prostaglandin derivative of formula (A): which comprises reacting an aldehyde represented by formula (1): with a 2-oxoalkyl phosphonate in a reaction solvent under the presence of alkali hydroxide as sole base. By carrying out the reaction using an alkali hydroxide as sole base in the reaction system, the desired prostaglandin derivative can be obtained by simple procedures and with high yield.

Abstract: Disclosed is a method for preparing a prostaglandin derivative of formula (A): which comprises reacting an aldehyde represented by formula (1): with a 2-oxoalkyl phosphonate in a reaction solvent under the presence of alkali hydroxide as sole base. By carrying out the reaction using an alkali hydroxide as sole base in the reaction system, the desired prostaglandin derivative can be obtained by simple procedures and with high yield.

Abstract: A choline salt crystal of (1S)-1,5-anhydro-1-[5-(azulen-2-ylmethyl)-2-hydroxyphenyl]-D-glucitol which shows an endothermic peak at 194 to 198° C. as measured by differential scanning calorimetry (DSC analysis) and shows main peaks at about 2? (°) 5.58, 14.72, 16.80, 17.82, 21.02, and 22.46 as measured by X-ray powder diffraction. Thus, a crystal of an azulene compound can be produced which is in a single crystal form, has a constant quality, can be produced with good reproducibility, can be provided stably as a crystal of an drug substance for use in the preparation of a pharmaceutical and is excellent in storage stability.

Abstract: This invention describes protected 5,7-dihydroxy-4,4-dimethyl-3-oxoheptanoic acid ester and 5,7-dihydroxy-2-alkyl-4,4-dimethyl-3-oxoheptanoic acid ester for the synthesis of epothilones and epothilone derivatives and process for the production of these esters.

Abstract: A monomer represented by the following general formula (m-1): wherein R is a group having an alicyclic skeleton, R2s may be the same or different and are individually hydrogen atom, halogen atom or monovalent organic group, X1 is a bivalent organic group containing a heteroatom, j is an integer of 0 to 3, and R1 is a group selected from the following groups, a monovalent organic group having Si (R1-1), and —(X2)k—R4—(X3)m—C(R6)3  (R1-2), wherein X2 and X3 are a bivalent organic group containing a heteroatom, k and m are an integer of 0 to 3, R4 is a bivalent alkyl group, R6s may be the same or different and are individually hydrogen atom, halogen atom or monovalent organic group.

Abstract: A process of making arbutin and its derivatives comprises solvolyzing an acylated precursor of arbutin or its derivative in a solution comprising an organic solvent and a base, neutralizing the solution with an acid, and crystillizing the product arbutin or its derivative. The process may be employed on an industrial scale and avoids the use of ion exchange columns. The process has the advantages of not requiring ion exchange columns and peripheral devices, which leads to cost and time savings, due to the elimination of column regeneration steps. Waste water from column regeneration is also eliminated.

Abstract: Pharmaceutical compositions which are useful for the treatment of cancer or illnesses which arise due to an abnormally elevated cell proliferation comprise acyl derivatives of aromatic aldehydes, especially arylidene diesters and .alpha.-alkoxyarylidene esters of general formula (I).

Abstract: Sordarin derivatives are antifungal agents useful in the treatment and/or prevention of human and animal fungal infections, as well as in the control of phytopathogenic fungi in crops.

Abstract: Chiral compounds of the formula I ##STR1## where R.sup.1 is hydrogen or --Y--Z--Y.sup.1,R.sup.2 is ##STR2## and X is hydrogen, fluorine, chlorine, bromine, iodine, hydroxyl or OR.sup.1, whereY is a direct bond, CO or C.sub.2 - to C.sub.8 -alkylene in which nonadjacent carbon atoms may be replaced by O, CO, COO or OCO,Z is a group containing one or more saturated or unsaturated carbocyclic or heterocyclic rings,Y.sup.1 is C.sub.1 - to C.sub.15 -alkyl, C.sub.2 - to C.sub.15 -alkenyl, C.sub.1 - to C.sub.15 -alkoxy, C.sub.2 - to C.sub.15 -alkenyloxy, C.sub.1 - to C.sub.15 -alkanoyloxy or C.sub.3 - to C.sub.15 -alkenoyloxy, it being possible for nonadjacent carbon atoms in these radicals to be replaced by oxygen, OCO or COO, andn is 0, 1 or 2.

Abstract: The present invention relates to a novel process for preparing cis-4-O-protected-substituted-2-cyclopentenol derivatives comprising, a) dissolving a 4-O-protected-2-cyclopentenone in a suitable organic solvent; and b) treating the solution with a suitable Lewis acid and a suitable reducing agent at a temperature of from about -100.degree. C. to about 20.degree. C. The cis-4-O-protected-substituted-2-cyclopentenol derivatives are useful intermediates in the preparation of various cyclopentanyl and cyclopentenyl purine analogs which are useful as immunosuppressants and in the preparation of various prostaglandins.

Abstract: The present invention relates to a novel process for preparing cis-4-O-protected-substituted-2-cyclopentenol derivatives comprising, a) dissolving a 4-O-protected-2-cyclopentenone in a suitable organic solvent; and b) treating the solution with a suitable Lewis acid and a suitable reducing agent at a temperature of from about -100.degree. C. to about 20.degree. C. The cis-4-O-protected-substituted-2-cyclopentenol derivatives are useful intermediates in the preparation of various cyclopentanyl and cyclopentenyl purine analogs which are useful as immunosuppressants and in the preparation of various prostaglandins.

Abstract: The present invention provides a compound represented by the formula: ##STR1## wherein R.sub.1 denotes a hydrogen atom or a methyl group; R.sub.2 represents a 1-methyl-2-propenyl group, a 1-methyl-2-propynyl group, a 3,3-dihalogeno-1-methyl-2-propenyl group or a C.sub.1 -C.sub.6 alkyl group which may be substituted with at least one halogen atom; and A' represents a hydrogen atom or a protecting group for a hydroxyl group. The compound is useful in the preparation of esters which can be used to control insect pests.

Abstract: A novel process for the production of a compound represented by the formula: ##STR1## wherein Z and Z' each represents a protective group for the hydroxyl group; R.sup.1 represents a hydrogen atom or an alkyl group; R.sup.2 represents an alkyl group, a cycloalkyl group, an alkenyl group, an alkynyl group, a group represented by the formula --B--D (in which B is an alkylene group and D is a substituted or unsubstituted phenyl group, a substituted or unsubstituted phenoxy group or a cycloalkyl group), a substituted or unsubstituted phenyl group or a substituted or unsubstituted phenoxy group; R.sup.3 and R.sup.4 each represents a hydrogen atom, an alkyl group or an alkoxy group; R.sup.5 represents a hydrogen atom, an alkyl group, an alkoxy group, a halogen atom, a cyano group, an amino group, a hydroxyl group or a group represented by a formula --COOR.sup.8 ; R.sup.6 represents a group represented by a formula --COOR.sup.9, a cyano group, a hydroxyl group, a group represented by a formula --OCOR.sup.

Abstract: The invention is drawn to a compound having the following formula ##STR1## in which X.sup.1 and X.sup.2, which may be the same or different, represent hydrogen or a hydroxy-protecting group, X.sup.4 is hydrogen, A is selected from --COOAlkyl and CH.sub.2 OH, and B is a hydroxy group, or A and B, when taken together, represent an oxo group. These compounds are useful as intermediates in the production of 19-nor vitamin D derivatives.

Abstract: A process for the production of a cyclopentenol compound represented by the formula I: ##STR1## wherein R.sub.1 represents a 2-propenyl group or a 2-propynyl group from a cyclopentenolone compound represented by the formula II: ##STR2## by protecting the hydroxyl group of the compound II, reacting the protected compound II with a reagent system obtained from TiCl.sub.4, Zn and CH.sub.2 Br.sub.2 or CH.sub.2 I.sub.2 and removing the protecting group from the resulting reaction product.

Abstract: Compounds of Formula 1 ##STR1## wherein X is S or O; R.sub.1 -R.sub.5, m, o, X, Y, A, B are as defined in the specification.

Abstract: The invention describes intermediates for use in the synthesis of 1.alpha.-hydroxy-19-nor-vitamin D compounds. The intermediates have the following formula: ##STR1## The disclosed process includes (a) the construction of a 5,8-diol-6-yne intermediate by joining ring-A and ring-C/D portions of the desired end product via the condensation of an acetylenic derivative containing the C/D-ring portion of the desired end product with a cyclic dihydroxy ketone representing the A-ring of the desired end product; (b) the partial reduction of the 6,7 acetylenic triple bond linkage between the A and C/D ring portions to obtain a 5,8-diol-6-ene intermediate; and (c) the reductive removal of the 5,8-oxygen functions to generate the required 5,7-diene end product from which the desired 7-trans(7E)-isomer is purified directly, or after optional double bond isomerization of the 7-cis(7Z)-isomer employing a novel thiophenol-promoted isomerization step.

Abstract: Improvement in the technique of synthesizing prostaglandins, particularly those having at least one halogen atom at the 16- or 17-position, which comprises introducing a .omega. chain into the aldehyde thereby to enable considerable yield improvement in the production of .alpha.,.beta.-unsaturated ketones, and which does not involve hydrogen generation and can insure safe operation.A method of producing .alpha.,.beta.-unsaturated ketones by reacting aldehyde with 2-oxoalkyl phosphonate, wherein the reaction was carried out under the presence of a base and a zinc compound.

Abstract: The present invention relates to cyclopentane heptanoic or cyclopentane heptenoic acid, 2-hydrocarbyl sulfonamidomethyl, and derivatives thereof, useful as therapeutic agents. In particular, the therapeutic agents of this invention are useful as ocular hypotensives.

Abstract: A 2,6,7-trisubstituted-3-methylenebicyclo-[3.3.0]octane of formula (I) or an enantiomer thereof, or a mixture of these in an arbitrary ratio. The compound is a key intermediate for preparation of isocarbacyclins which are useful as medicines for the circulatory system such as an antithrombotic agent, an antilipidemic agent, a hypotensive agent or an antiarterosclerotic agent.

Abstract: 2-Substituted-2-cyclopentenones represented by the formula (I): ##STR1## wherein A is a hydroxyl group or ##STR2## and B is a hydrogen atom or A and B are bonded together to form one bonding arm;R.sup.1 represents a substituted or unsubstituted hydrocarbon group having 1 to 10 carbon atoms;R.sup.2 represents a substituted or unsubstituted aliphatic hydrocarbon group having 1 to 10 carbon atoms;R.sup.3 represents a substituted or unsubstituted aliphatic hydrocarbon group having 1 to 10 carbon atoms; wherein,when R.sup.3 is a single bond bonded to the cyclopentene skeleton, X represents a hydrogen atom, a hydroxyl group or a protected hydroxyl group; andwhen R.sup.3 is a double bond bonded to the pentene skeleton, X represents a bonding arm constituting a part of said double bond; andm and n independently represent 0, 1 or 2.

Abstract: Compounds of the formula ##STR1## wherein R.sup.1 denotes a group R.sup.3 or R.sup.3 --A.sup.4 --Z.sup.3 -- and R.sup.2 denotes a group R.sup.4 or --Z.sup.4 --A.sup.5 --R.sup.4 ; m and n each individually stand for the number 0 or 1; A.sup.1, A.sup.2, A.sup.3, A.sup.4 and A.sup.5 each independently represent unsubstituted or halogen-, cyano- and/or methyl-substituted 1,4-phenylene in which optionally 1 CH group or 2 CH groups is/are replaced by nitrogen, trans-1,4-cyclohexylene in which optionally 2 non-adjacent methylene groups are replaced by oxygen and/or sulphur, 1-cyano-trans-1,4-cyclohexylene, bicyclo[2.2.2]octane-1,4-diyl, naphthalene-2,6-diyl, tetralin-2,6-diyl or trans-decalin-2,6-diyl; Z.sup.1, Z.sup.2, Z.sup.3 and Z.sup.4 each independently signify a single covalent bond, --COO--, --OOC--, --CH.sub.2 O--, --OCH.sub.2 --, --CH.sub.2 CH.sub.2, --C.tbd.C--, --(CH.sub.2).sub.3 O--, --O(CH.sub.2).sub.3 -- or the trans form of --CH.dbd.CH--CH.sub.2 O-- or --OCH.sub.2 --CH.dbd.CH--; R.sup.3 and R.sup.

Abstract: A process for the manufacture of compounds of the general formula ##STR1## wherein R.sup.1 signifies hydroxy or an etherified hydroxy group, and of zeaxanthin by converting a compound of the general formula ##STR2## wherein R.sup.1 has the above significance, in an inert organic solvent into the acetylenide and reacting this with methyl vinyl ketone, reducing the alcoholate obtained or the alcohol (obtained after hydrolysis of the alcoholate) of the general formula ##STR3## wherein R.sup.1 has the above significance, and subsequently hydrolyzing to give the compound of formula IV and, if desired, converting the compound of formula IV obtained into zeaxanthin.

Abstract: The invention relates to a process for manufacturing optically active carbacyclin intermediate products from racemic cis-bicyclo[3.3.0]octane-2-carboxylic acids. This process makes it possible in an advantageous way to produce important intermediates for the synthesis of stable and pharmacologically active carbacyclin derivatives.

Abstract: A process for producing carotenoids and carotenoid intermediates via reduction of sulfonyl polyenes with a dithionite in the presence of ammonia or an aliphatic amine, including novel intermediates in this process, which carotenoids are known coloring agents for foodstuffs, animal feeds, pharmaceuticals, etc.

Abstract: There are disclosed a (2-chloro-3-oxo-1-alkenyl)-bicyclo[3.3.0 octene derivative represented by the formula: ##STR1## wherein R.sup.1 represents --CH.sub.2 CH.sub.2 CH.sub.2 COOR.sup.5, --CH.sub.2 CH.sub.2 --O--CH.sub.2 COOR.sup.5, --CH.dbd.CHCH.sub.2 COOR.sup.5 or --CH.sub.2 CH.sub.2 C.tbd.C--COOR.sup.5 group where R.sup.5 in the groups represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms; R.sup.2 represents a hydrogen atom, an acyl group having 1 to 7 carbon atoms, a tri(1 to 7 carbon atoms)-hydrocarbylsilyl group or a group forming an acetal bonding with an oxygen atom of a hydroxy group; R.sup.

Abstract: Compounds of formula (C) ##STR1## where either R.sup.D represents a hydroxymethyl group and R.sup.E represents a hydroxyl group or R.sup.D represents a protected hydroxymethyl group and R.sup.E represents a protected hydroxyl group or R.sup.E represents a hydroxyl group and R.sup.D represents an ethenyl group and R.sup.F represents a hydroxyl or protected hydroxyl group or a leaving group with the proviso that either R.sup.D represents a protected hydroxymethyl group and R.sup.E represents a protected hydroxyl group or R.sup.F represents a protected hydroxyl group, which compounds are of use as intermediates in the preparation of compounds having antiviral activity.

Abstract: The present invention provides a novel 6-nitroprostaglandin derivatives of the formula (I) ##STR1## wherein A, n, R.sup.1, R.sup.2, R.sup.3, R.sup.4 and R.sup.5 are as defined in claim 1.The 6-nitroprostaglandin derivatives is useful as medicines because of its excellent pharmacological activities including platelet aggregation inhibiting activity, blood pressure lowering activity and anti-ulcerous activity, and useful as intermediate for other pharmaceutically active compounds such as 6-oxoprostaglandin derivatives, prostaglandin E.sub.1 derivatives, etc.

Abstract: Bicyclo[3.3.0]octenylaldehyde derivatives represented by the formula: ##STR1## wherein R.sup.1 is a substituent selected from the group consisting of a hydrogen atom and a protective group of a hydroxy group;R.sup.2 is a substituent selected from the group consisting of --CH.sub.2 OR.sup.5, ##STR2## where R.sup.5 is a substituent selected from the group consisting of a hydrogen atom and a protective group of a hydroxy group,R.sup.6 is a substituent selected from the group consisting of an alkyl group, an alkenyl group and an alkynyl group, said substituent being straight, branched or cyclic and having 5 to 10 carbon atoms,X is a substituent selected from the group consisting of a vinylene group and an acetylene group, andR.sup.7 is a substituent selected from the group consisting of an alkyl, an alkenyl group, and an alkynyl group, said substituent being straight, branched or cyclic and having 5 to 10 carbon atoms; andR.sup.

Abstract: A method for preparing a cis-bicyclo[3.3.0]octylidene derivative represented by the formula: ##STR1## wherein R.sup.1 is a hydrogen atom or an alkyl group; R.sup.2 is a hydrogen atom or a protective group for hydroxyl group; and Y is ##STR2## where R.sup.3 is a hydrogen atom or a protective group for hydroxyl group; R.sup.4 is a hydrogen atom or a straight, branched or cyclic alkyl group, alkenyl group or alkynyl group; and X is a group represented by CH.dbd.CH or C.tbd.C,comprises carrying out the catalytic hydrogenation reaction of a (1-alkenyl)-cis-bicyclo[3.3.0]octene derivative represented by the formula: ##STR3## wherein R.sup.1, R.sup.2 and Y have the same meanings as defined above, in the presence of a metal carbonyl compound or its complex represented by the formula:Mw(CO)x(H)y(R)zwherein M is a metal element of the group VIB; R is a .pi. ligand or a phosphine ligand; w is 1 or 2; x is an integer of 3 to 6; y is 0 or 1; and z is 0 or an integer of 1 to 3.

Abstract: Process for the preparation of bicyclic ketones containing blocked hydroxy groups, of general Formula I ##STR1## wherein R.sub.1 is the residues --CH.sub.2 OR.sub.2 wherein R.sub.2 means benzyl, dimethyl-tert-butylsilyl, diphenyl-tert-butylsilyl, dimethylphenylsilyl, tribenzylsilyl, or tetrahydropyranyl, ##STR2## with R.sub.2 having the meanings given above, R.sub.4 meaning hydrogen or methyl, and R.sub.5 meaning a straight-chain or branched-chain, saturated or unsaturated alkyl residue which can contain fluorine, chlorine, 1,2-methylene, 1,1-trimethylene, or methoxy substitutents, or a CH.sub.2 --X-Aryl residue with X meaning CH.sub.2 or O and Aryl meaning phenyl or a heterocyclic residue, which residues can be substituted by methyl, methoxy, fluorine, chlorine, bromine, or trifluoromethyl, or ##STR3## with the meanings for R.sub.2, R.sub.4, and R.sub.5 as indicated above, and R.sub.3 having the meanings set forth for R.sub.2, it being possible for R.sub.3 to be identical to R.sub.2 or different from R.sub.

Abstract: A compound of the formula ##STR1## wherein X.sup.1 is a free or an esterified carboxyl group, or a group of the formula: ##STR2## (R.sup.a and R.sup.b are each independently a hydrogen atom, a C.sub.1 -C.sub.4 alkyl group, a C.sub.3 -C.sub.7 cycloalkyl group, a benzyl group, a phenyl group, a phenyl group substituted with a halogen atom or a C.sub.1 -C.sub.4 alkyl group, or, when taken together with the adjacent nitrogen atom to which they are attached, they represent a 5 to 7 membered saturated heterocyclic group), Y is a group of the formula: ##STR3## (R.sup.6 is a hydrogen atom or a C.sub.1 -C.sub.4 alkyl group) or ##STR4## (R.sup.6 is as defined above), R.sup.1 is a hydrogen atom, a hydroxyl group or a protected hydroxyl group, R.sup.2 is a hydrogen atom or R.sup.1 and R.sup.2, when taken together, mean a single linkage to form a double bond between the carbon atoms which they are linked, R.sup.3 is a hydroxyl group or a protected hydroxyl group, R.sup.4 is a hydrogen atom or a C.sub.1 -C.sub.

Abstract: Compounds of Formula I ##STR1## wherein X is oxygen or CH.sub.2 ;A is CH.sub.2 --CH.sub.2, trans-CH.dbd.CH or C.tbd.C;W is free or functionally modified hydroxymethylene or free or functionally modified ##STR2## and the OH groups may be in the .alpha.- or the .beta.-position; D is straight chain or branched, saturated or unsaturated hydrocarbon aliphatic of from 1 to 10 carbon atoms, which may be substituted by fluorine;E is C.tbd.C or CR.sub.3 .dbd.CR.sub.4, R.sub.3 and R.sub.4 being different and being hydrogen or alkyl of 1 to 5 carbon atoms;R.sub.1 is free or functionally modified hydroxy; andR.sub.2 is alkyl, cycloalkyl, optionally substituted aryl or heterocyclic,have valuable pharmacological properties, e.g., hypotensive and bronchodilatory characteristics. They can furthermore be used for prophylaxis and therapy of coronary infarct and as a treatment for stroke. They are produced by means of reduction of the corresponding 1-carbonic acid derivatives.

Abstract: A conjugate addition reaction and novel intermediate compounds are disclosed, whereby the reaction of ##STR1## with a lithio-cuprate reagent ##STR2## produces compounds of the class: ##STR3## A new process is disclosed for preparing 1-(methyl)-16,16-(dimethyl)-11-alpha-15-alpha-dihydroxy-9-oxo-2,13,trans,t rans-prostadienoate, and congeners thereof, including racemic mixtures.

Abstract: Novel compounds of the following general formula: ##STR1##

Abstract: A novel 3-endo-protected hydroxyl-tricyclo[3,2,0,0.sup.2,7 ]heptan-6-one is described which can be alkylated stereospecifically to give a 5-endo-protected hydroxyl-bicyclo[2,2,1]heptan-2-one which may then be converted via a sequence of reactions into prostaglandins of the F-series having a protecting group at the 9-position. The synthesis of the tricyclo[3,2,0,0.sup.2,7 ]heptan-6-one is also described.

Abstract: Compounds of the general formula I are disclosed as useful intermediates in the preparation of prostanoids: ##STR1## wherein A represents O or H, OR.sub.z ;R.sup.z represents hydrogen or a protecting group;R.sup.x represents hydrogen or a protecting group; andR.sup.y represents halogen, a substituted thio group, di-substituted amino group, or a group of the formula R.sup.2, and R.sup.2 represents a straight-or branched-chain alkyl alkenyl or alkynyl group which may optionally be substituted by one or more carboxyl, carboxylic acid ester, or free or protected hydroxyl, thiol, aldehyde or keto groups;with the provisos that R.sup.x is not hydrogen when A is O and R.sup.y is R.sup.2 ; and that when A is H, OR.sup.z R.sup.y is R.sup.2 and R.sup.x and R.sup.z are not both hydrogen.Processes for the preparation of these compounds and of 2-substituted 4-hydroxy-cyclopent-2-en-1-one derivatives are also disclosed.

Abstract: A process for preparing a 3-oxo-7-hydroxy-bicyclo[3,3,0]octan-2-ylcarboxylic acid ester of the formula ##STR1## wherein R.sub.1 is alkyl of 1-6 carbon atoms or phenalkyl of 7-10 carbon atoms andR.sub.2 is hydrogen, alkyl or 1-6 carbon atoms, phenalkyl of 7-10 carbon atoms, tetrahydropyranyl, tetrahydrofuranyl, .alpha.-ethoxyethyl, tri-C.sub.1-4 -alkylsilyl, wherein the alkyl moieties can optionally be substituted by phenyl, or ##STR2## wherein R.sub.3 is alkyl of 1-6 carbon atoms or aryl of 6-12 carbon atoms, comprises oxidizing the corresponding 7-hydroxy-2-oxabicyclo [3,3,0]octan-3-ylideneacetic acid ester of the formula ##STR3## wherein R.sub.1 and R.sub.2 are as defined above, to form the corresponding ketone, reacting the latter with a base which opens the ether oxygen containing ring, and then reducing the resultant product to prepare the 3-oxo-7-hydroxy-bicyclo[3,3,0]octan-2-ylcarboxylic acid ester.