Abstract: The present invention relates to a process for the preparation of astaxanthin having the formula ##STR1## comprising the step of oxidizing a dienolether, a dienamine, or a dienolate anion of canthaxanthin with an oxaziridine oxidant to produce an astaxanthin dihemiaminal, and then decomposing the dihemiaminal to produce astaxanthin. The process advantageously involves two less steps than the best known prior art process for the preparation of astaxanthin.The invention also relates to important intermediates in the preparation of astaxanthin, which is itself an important additive in the fish industry, the most important of which intermediates is the astaxanthin dihemiaminal.

Abstract: Process for the preparation of herbicidally active substituted cyclohexan-1,3,5-triones which comprises either(a) reacting a compound of formula (II) ##STR1## wherein R.sup.2, R.sup.3, R.sup.4 and R.sup.5 are, for example, hydrogen or C.sub.1 -C.sub.4 alkyl with a compound of formula (III):R.sup.1 COCN (III)wherein R.sup.1 is optionally substituted aryl in the presence of a base and a Lewis acid; or(b) reacting a compound of formula (VI) ##STR2## with a compound of formula (X) ##STR3## in the presence of a Lewis acid; or (c) where R.sup.2, R.sup.3, R.sup.4 and R.sup.5 are the same, reacting a compound of formula (XI) ##STR4## with a compound of formula R.sup.3 X' in the presence of a base, wherein X' is a leaving group.

Abstract: Cyclopentanones of the general formula I ##STR1## where R.sup.1 and R.sup.2 are each an organic radical or R.sup.1 or R.sup.2 may be hydrogen and R.sup.3 is hydrogen or formyl, are prepared by a process in which a 2-formyl-3,4-dihydropyran of the general formula II ##STR2## where R.sup.1 and R.sup.2 have the abovementioned meanings, a) where R.sup.3 is formyl, is converted in the presence of an acidic heterogeneous catalyst at from 50.degree. to 500.degree. C., andb) where R.sup.3 is hydrogen,b.sub.1) is reacted with water or an alcohol in the presence of an acidic heterogeneous catalyst at from 100.degree. to 500.degree. C. in the gas phase orb.sub.2) a compound II or an acrolein of the general formula III ##STR3## is reacted with water or with water in the presence of an acid or with an alcohol in the presence of an acid at from 150.degree. to 400.degree. C. in the liquid phase. Novel 2-formylcyclopentanones are obtained.

Abstract: A process for preparing .alpha.,.alpha.-dialkoxy ketones of the formula I ##STR1## where R.sup.1 and R.sup.2 are each, independently of one another, hydrogen, C.sub.1 -C.sub.20 -alkyl, C.sub.3 -C.sub.20 -cycloalkyl, C.sub.4 -C.sub.30 -cycloalkylakyl, C.sub.9 -C.sub.30 -alkylcycloalkyl, unsubstituted or C.sub.1 -C.sub.8 -alkyl, C.sub.1 -C.sub.8 -alkoxy-, halogen-, C.sub.1 -C.sub.4 -haloalkyl-, C.sub.1 -C.sub.4 -haloalkoxy-, phenyl-, phenoxy-, halophenyl-, halophenoxy- and/or cyano-substituted aryl, C.sub.7 -C.sub.20 -aralkyl or heterocyclyl,R.sup.2 is also ##STR2## R.sup.3 and R.sup.4 are each, independently of one another, C.sub.1 -C.sub.20 -alkyl, C.sub.3 -C.sub.20 -cycloalkyl, aryl, C.sub.7 -C.sub.20 -arylalkyl, or together are an unsubstituted or C.sub.1-C.sub.4 -alkyl- substituted C.sub.2 -C.sub.7 -alkylene chain andR.sup.5 is R.sup.1 or together with R.sup.1 is an unsubstituted or C.sub.1 -C.sub.4 -alkyl-substituted C.sub.2 -C.sub.

Abstract: There are provided 4,5-Dihydroxy-2,6,6-trimethyl-2-cyclohepten-1-one, a method for preparing the same and an antiulcer agent containing the same as an effective ingredient.

Abstract: A 3-amino-2-hydroxybornane derivative represented by formula (I): ##STR1## wherein R represents a furfuryl group, a 1-methylpyrrolylmethyl group, or a benzyl group, is disclosed. The compound is useful as a ligand in an asymmetric Michael reaction, particularly for the production of an optically active muscone.

Abstract: 3-Hydroxy-2-cyclobuten-1-one salts of the general formula: ##STR1## wherein R is an ammonium group of the general formula: ##STR2## wherein R.sub.1, R.sub.2 and R.sub.3 are the same or different in meaning and each is a hydrogen atom, a lower alkyl group or a cycloalkyl group or R is an alkali metal atom. The salts according for formula I are obtained by the reaction of pure 3-acetoxy-2-cyclobuten-1-one, or 1,3-cyclobutanedione or a distillation residue of the diketene production containing 3-acetoxy-2-cyclobuten-1-one, with a base. The base can be an amine of the general formula: ##STR3## wherein R.sub.1, R.sub.2, and R.sub.3 have the above-mentioned meaning, or an alkali metal alcoholate or an alkali metal hydroxide. The salts according to formula I are suitable for the production of squaric acid, by their being halogenated in a first step and then being hydrolyzed to squaric acid in a second step.

Abstract: 3-Hydroxy-2-cyclobuten-1-one salts of the general formula: ##STR1## wherein R is an ammonium group of the general formula: ##STR2## wherein R.sub.1, R.sub.2 and R.sub.3 are the same or different in meaning and each is a hydrogen atom, a lower alkyl group or a cycloalkyl group or R is an alkali metal atom. The salts according for formula I are obtained by the reaction of pure 3-acetoxy-2-cyclobuten-1-one, or 1,3-cyclobutanedione or a distillation residue of the diketene production containing 3-acetoxy-2-cyclobuten-1-one, with a base. The base can be an amine of the general formula: ##STR3## wherein R.sub.1, R.sub.2, and R.sub.3 have the above-mentioned meaning, or an alkali metal alcoholate or an alkali metal hydroxide. The salts according to formula I are suitable for the production of squaric acid, by their being halogenated in a first step and then being hydrolyzed to squaric acid in a second step.

Abstract: The present invention relates to a process for the preparation of astaxanthin having the formula ##STR1## comprising the step of oxidizing a dienolether, a dienamine, or a dienolate anion of canthaxanthin with an oxaziridine oxidant to produce an astaxanthin dihemiaminal, and then decomposing the dihemiaminal to produce astaxanthin. The process advantageously involves two less steps than the best known prior art process for the preparation of astaxanthin.The invention also relates to important intermediates in the preparation of astaxanthin, which is itself an important additive in the fish industry, the most important of which intermediates is the astaxanthin dihemiaminal.

Abstract: The invention is directed to a process for the catalytic oxidation of an isoprenoid containing at least one allylic hydrogen atom, which process comprises reacting the isoprenoid with oxygen or an oxygen-containing gas in an inert solvent in the presence of a N-hydroxydicarboxylic acid imide of the formula ##STR1## wherein A-B stands for CH.sub.2 -CH.sub.2, CH.dbd.CH, an aromatic hydrocarbon residue or a group derived from one of these groups in which one or more hydrogen atoms is/are replaced by alkyl or halogen,to produce a primary of secondary hydroperoxide.The process of the invention is suitable for the manufacture of steroids, vitamins, odorant substances, carotinoids and the like.

Abstract: Disclosed is a novel inosose compound represented by the general formula: ##STR1## wherein X.sup.1 and X.sup.2 are both halogen; X.sup.1 is hydrogen and X.sup.2 is halogen; or X.sup.1 is --SQ.sup.1 and X.sup.2 is --SQ.sup.2 (each of Q.sup.1 and Q.sup.2 is lower alkyl or Q.sup.1 and Q.sup.2 may form lower alkylene), R.sup.1 is a protective group for hydroxyl and Y is .dbd.O, .dbd.N--Z (Z is hydroxyl which may be protected) or ##STR2## (A is hydrogen or an amine residue), particularly to the compound wherein the symbol Y is oxygen.The inosose compound is useful as intermediates for production of valiolamine and the N-substituted derivatives thereof, which have potent .alpha.-glucosidase inhibiting activities and are useful as preventives or therapeutics for symptoms of hyperglycemia and various diseases derived therefrom in human and animals, such as diabetes, obesity and hyperlipemia.

Abstract: A process for preparing oxocyclopentenes of the formula: ##STR1## wherein R.sup.1 is hydrogen, lower alkyl or lower alkenyl and R.sup.2 is hydrogen, lower alkyl, lower alkenyl, lower alkynyl, substituted or unsubstituted aryl, ar(lower)alkyl, thienyl or cycloalkyl, which comprises subjecting a furan-carbinol of the formula: ##STR2## wherein R.sup.1 is as defined above and R.sup.3 is hydrogen, lower alkyl, lower alkenyl, lower alkynyl, substituted or unsubstituted aryl, ar(lower)alkyl, thienyl or cycloalkyl to rearrangement, subjecting the resultant hydroxycyclopentenone of the formula: ##STR3## wherein R.sup.1 and R.sup.3 are each as defined above to hydrogenation and subjecting the resulting hydroxycyclopentanone of the formula; ##STR4## wherein R.sup.1 and R.sup.2 are each as defined above to dehydration.

Abstract: A process for preparing compounds represented by the formula ##STR1## wherein: X is hydrogen or lower alkoxy;Y is hydrogen, exo-(lower alkyl) or endo-(lower alkyl);n is an integer from 2-4;R.sub.2 is hydrogen or methyl; andR.sub.3 is linear or branched alkyl, ##STR2## --(CH.sub.2).sub.m -phenyl or --CH.sub.2 O-phenyl; in which any phenyl may be optionally substituted with lower alkyl, lower alkoxy, trifluoromethyl, or halogen, anda is an integer of 0, 1 or 2;b is an integer of 3-7;m is an integer of 0, 1 or 2,as a mixture or separately in a sequence starting from an epoxide represented by the formula ##STR3## and processes for making the novel intermediates.

Abstract: A method for purifying a macrocyclic ketone is disclosed which comprises light-irradiating a macrocyclic ketone containing a macrocyclic diketone as an impurity. Preferably, the macrocyclic ketone as light-irradiated is treated with an active charcoal so as to elevate the purity of the resulting macrocyclic ketone. For light-irradiation, the macrocyclic ketone may be in the form of an alcohol solution.

Abstract: Beta acids, separated from hop extracts, are purified prior to hydrogenolysis by mixing with an aqueous solution of polyvalent metal ions, preferably edible ions such as magnesium or calcium ions, separating the aqueous beta acids from insoluble materials containing catalyst poisons, and recovering the thus-purified beta acids which are catalyst-poison free and in a form suitable for hydrogenolysis to 4-desoxy alpha acids.

Abstract: Alpha,beta-unsaturated ketones of the formula (I) ##STR1## where R.sup.1, R.sup.2 and R.sup.3 are each hydrogen, alkyl, alkenyl of 1 to 12 carbon atoms, cycloalkyl, aryl, aralkyl or alkylaryl, are prepared by converting the corresponding .alpha.-hydroxy, alkoxy or carboxy compound in the presence of an acidic catalyst.Preferred starting materials are 3-methyl-3-hydroxy-butan-2-one, 3-methyl-3-hydroxypentan-2-one and 3-pentamethylene-3-hydroxypropan-2-one, and preferred catalysts are zeolites of the pentasil type.

Abstract: Ketones of the formula ##STR1## where R.sup.1 to R.sup.3 are each hydrogen and R.sup.1 to R.sup.4 are each alkyl of 1 to 12 carbon atoms, cycloalkyl of 4 to 8 carbon atoms, aryl, aralkyl or alkylaryl, which each in turn may be substituted, or R.sup.1 and R.sup.2 and R.sup.3 together with the carbon atoms to which they are bonded form a cycloalkane, are prepared by reacting ketones of the formula ##STR2## where one of R.sup.1, R.sup.2, R.sup.3 and R.sup.5 is hydroxyl, alkoxy or carboxyl while the remaining R.sup.1 to R.sup.4 have the abovementioned meanings, with hydrogen in the presence of acid catalysts supporting one or more hydrogenation components, zeolites of the pentasil type being particularly suitable.

Abstract: Macrocyclic 2-halogenoketones are prepared by reacting a macrocyclic 2-hydroxyketone with a halogenating agent. This reaction may be carried out in the presence of a solvent and/or a catalyst.

Abstract: The invention relates to a process for preparing aromatic or hetero-aromatic aldehydes by the Reimer-Tiemann formylation reaction. The process comprises employing a solid alkaline hydroxide in order to carry out the reaction in a solid/liquid medium and by adjusting the initial hydration rate of the medium to be higher than 0.05 moles of water per mole of initial compound and less than 1.5 moles of water per mole of alkaline hydroxide initially in the medium. Such a process makes it possible to substantially increase the yield of the Reimer-Tiemann reaction and to avoid tar formation entirely or in large part.

Abstract: A process for preparing an optically active 2-substituted or unsubstituted-4-hydroxy-2-cyclopentenone of the formula: ##STR1## wherein R is a hydrogen atom, an allyl group or a propargyl group, which comprises reacting the corresponding 2-substituted or unsubstituted-4-hydroxy-2-cyclopentenone of the formula: ##STR2## wherein R is defined above with a lactone chosen from (1R,5S)-6,6-dimethyl-4-hydroxy-3-oxabicyc lo[3.1.0]hexan-2-one or (1S,5R)-6,6-dimethyl-4-hydroxy-3-oxabicyclo[3.1.0]hexan-2-one in a molar ratio of 1.5 - 2:1 in the presence of p-toluenesulfonic acid or benzenesulfonic acid in the coexistence of an organic solvent under elimination of water as an azeotropic mixture with the organic solvent to obtain a reaction mixture comprising (1R,5S)-6,6-dimethyl-3-oxa-4(R)-[1(R)-4-oxo-2-substituted or unsubstituted-2-cyclopentenyloxy]bicyclo[3.1.0]hexan-2-one or (1S,5R)-6,6-dimethyl-3-oxa-4(S)-[1(S)-4-oxo-2-substituted or unsubstituted-2-cyclopentenyloxy]bicyclo[3.1.

Abstract: Aldehydes can be condensed with ketones or aldehydes to produce higher aldehydes or ketones by contacting the materials to be condensed with a nonzeolitic molecular sieve. The condensation may be carried out in the presence of hydrogen to give as product a saturated aldehyde or ketone. The ketone and/or aldehyde may be generated in situ by dehydrogenation of an alcohol, and the hydrogen thus liberated used to effect hydrogenation of the immediate unsaturated product of the condensation, thereby producing as the final product a saturated aldehyde or ketone. The non-zeolitic molecular sieves can achieve improved conversion rates and selectivities as compared with conventional catalysts for the reaction.

Abstract: An improvement in a process for preparing a macrocyclic ketone having from 12 to 18 carbon atoms which comprises intramolecular cyclization of a lower alcohol diester of a straight chain alkanedicarboxylic acid having from 12 to 18 carbon atoms by acyloin condensation and reduction of the resulting 2-hydroxycycloalkanone is disclosed. The improvement comprises conducting the acyloin condensation in a water-immiscible organic solvent having a boiling point of not lower than 40.degree.C., subjecting the resulting organic solvent solution containing the 2-hydroxycycloalkanone to reduction, and conducting the reduction in the copresence of said organic solvent and water. The macrocyclic ketone can be prepared at high efficiency.

Abstract: Chloro-olefins which contain a group of the formula ##STR1## where Y is chlorine or hydrogen, which are prepared by a process in which a trichloromethyl compound which contains a group of the general formula ##STR2## where X is hydrogen or an organic radical, is reduced with a chromium(II) salt in an aqueous medium.

Abstract: A process for preparing cyclopentenone derivatives of the formula: ##STR1## wherein R.sup.1 is hydrogen, lower alkyl or lower alkenyl, R.sup.2 is hydrogen, lower alkyl, lower alkenyl, lower alkynyl, cycloalkyl, substituted or unsubstituted aryl or substituted or unsubstituted ar(lower)alkyl and A is the residue of a nucleophilic agent from which a hydrogen atom is excluded, which comprises reacting a 3-hydroxy-4-cyclopentenone compound of the formula: ##STR2## wherein R.sup.1 and R.sup.2 are each as defined above with a nucleophilic agent of the formulaA--H (III)wherein A is as defined above.The cyclopentenone derivatives of the formula (I) are useful as pharmaceuticals, agricultural chemicals, perfumes and as intermediates for the preparation of agricultural chemicals, pharmaceuticals and perfumes.

Abstract: A method for the dehydroxylation of alpha-hydroxyketone using lithium diphenylphosphide. The alpha-hydroxyketone, e.g. benzoin, is reacted with a solution of lithium diphenylphosphide followed by the addition of either an alkyl halide, e.g. methyliodide, or an alkyl halide and an organic acid, e.g. acetic acid, to yield the dehydroxylated compound, e.g. desoxybenzoin.

Abstract: .alpha.-Methyl-substituted ketones are prepared by reacting the corresponding unsubstituted ketones, which must possess two or more geminal hydrogen atoms in the .alpha.-position, with methanol in the gas phase at from 350.degree. to 500.degree. C. and under from 1 to 20 bar in the presence of a metal oxide.

Abstract: A novel process for the manufacture of quinone derivatives is described.In this process a compound of the formula ##STR1## is reacted with a compound of the formula ##STR2## and the resulting compound of the formula ##STR3## is subjected to a retro-Diels-Alder reaction. The substituents R.sup.1, R.sup.2, R.sup.3 and R.sup.4 have the significance given in the description.

Abstract: Beta-acids are separated from alpha-acids in a hop extract without using organic solvents by bubbling CO.sub.2 through an aqueous hop extract having a pH of about 9.6 to about 13 to lower the pH to about 8.5 to about 9.5 to precipitate the beta-acids and leave the alpha-acids in the extract.

Abstract: A novel process for the manufacture of cyclohexene derivatives which are suitable as intermediates for the manufacture of rhodoxanthin or zeaxanthin, as well as a process for the manufacture of rhodoxanthin or of zeaxanthin itself. The invention is also concerned with a novel starting material and novel intermediates in this process.

Abstract: Described in an isomer-directed process for producing asymmetric ketones defined according to the generic structure: ##STR1## wherein one of Z.sub.1 or Z.sub.2 is the moiety: ##STR2## and the other of Z.sub.1 or Z.sub.2 is hydrogen; wherein R.sub.11 and R.sub.21 represent hydrogen or the same or different alkyl or alkenyl with the proviso that R.sub.11 and R.sub.21 are not both hydrogen or wherein R.sub.11 and R.sub.21 taken together:(i) complete a cycloalkyl, cycloalkenyl, bicycloalkyl, mono or polyalkyl cycloalkyl or mono or polyalkyl cycloalkenyl ring, or(ii) represent alkylidene, cycloalkenyl alkylidene, aralkylidene, mono or polyalkyl cycloalkenyl alkylidene or mono or polyalkyl aralkylidene;and wherein R.sub.6, R.sub.7 and R.sub.

Abstract: Spiro[5.5]undeca-1,4,8-trien-3-ones are prepared by reacting a phenol having a free p-position with formaldehyde, a nitrogen compound selected from ammonia and primary and secondary amines, and a conjugated diene in an inert solvent at a temperature of at least about 190.degree. C.

Abstract: Process for the preparation of the compounds of the formulae Ia and Ib ##STR1## wherein A. 2,4,4-trimethylcyclohex-2-en-1-one oxime of the formula IIb ##STR2## is treated with a strong aqueous acid at from 30.degree. to 80.degree. C., preferably 40.degree. to 70.degree. C.,B. the resulting ketone of the formula IIIb ##STR3## is oxidized in a conventional manner, and C. if desired, the resulting compound Ib is isomerized in a conventional manner.Compounds of the formula A ##STR4## where R is one of the following radicals: --CH(OH)--CH.sub.2 --CH.dbd.CH.sub.2 (IIIb), --CH(OH)--CH.sub.3 (IIIc), --CH.sub.2 OH (IIId), --CH(OH)--CH.dbd.CH.sub.2 (IIIe), --CH(OCOCH.sub.3)--CH.sub.3 (IIIf), --CH.sub.2 --OCOCH.sub.3 (IIIg), --CO--CH.sub.2 --CH.dbd.CH.sub.2 (Ib), --CO--CH.sub.3 (Ic) and --CO--CH.dbd.CH.sub.2 (Ie).The compounds IIIb to IIIg, Ib, Ic and Ie are useful scents and aromas, and furthermore may become important intermediates for novel carotenoids.

Abstract: The compound 6-acetyl-4a,5,6,7,8,8a-hexahydro-1(4H)-naphthalenone, and preparation thereof beginning from 2-(2-hydroxyethyl)bicyclo[2.2.2] oct-5-ene.

Abstract: Catalysts and a method of using said catalysts for the alkoxylation of a variety of materials is disclosed. Catalysts so described produce alkoxylates having a very sharp alkoxylate distribution. The catalysts are supported and unsupported dialkoxy and dialkyl metal fluorides and halides and alkyl metal difluorides and dihalides.

Abstract: Disclosed is a method for the preparation of ketones by a catalytic vapor phase reaction of using reactants such as ketones with carboxylic acids and/or carboxylic acid precursors. An example of such a reaction is that of acetone with pivalic acid over a ceria-alumina catalyst at a temperature of nearly 470.degree. C. to produce pinacolone.

Abstract: New acetylenic and allenic carbinols of formula ##STR1## respectively, wherein symbol R stands for a trialkyl-silyl or a C.sub.1 to C.sub.6 alkyl radical, preferably a methyl, a tert-butyl or an isoamyl radical, or a group of formula ##STR2## wherein, when taken separately, each of symbols R.sup.1 and R.sup.2 represents a lower alkyl radical or, when taken together, R.sup.1 and R.sup.2 represent a tetramethylene group, are useful intermediates for the preparation of .beta.-damascenone.

Abstract: Described is a novel process for preparing allyl alpha and beta ionones defined according to the structure: ##STR1## wherein one of the dashed lines represents a carbon-carbon double bond and the other of the dashed lines represents a carbon-carbon single bond; and wherein the wavy lines represent the cis or trans juxtaposition of the acyl and cyclohexenyl rings about the carbon-carbon double bond which is alpha to the acyl moiety, and intermediates used in said process defined according to the structure: ##STR2## wherein the wavy lines and dashed lines are defined supra and wherein R.sub.1 represents hydrogen or allyl and Z represents methyl or OR.sub.2 and wherein R.sub.2 represents methyl or ethyl.

Abstract: Novel lactonic derivatives and their use as starting materials for preparing macrocyclic hydroxyketones useful as intermediates in the preparation of fragrant compounds.

Abstract: This invention relates to a process for the reduction of .alpha.-,.beta.-unsaturated linear homo- and heterocyclic ketones by a transfer of hydrogen from an alcohol donor to said unsaturated ketone. The alcohol donor must be unsubstituted or substituted with an inert group. Also the alcohol donor may be a primary or secondary alcohol or a glycol. The process is a catalytic one and is carried out in the presence of complexed iridium and rhodium catalysts of the following formulae: ##STR1## wherein: M is selected from Ir and Rh;Chel represents a kelating bidentate nitrogenous compound;L--L represents a molecule of a preferably not conjugated diolefin, or two molecules of a mono-olefin;X.sup.- represents an anion selected from among: Cl.sup.-, Br.sup.-, J.sup.- ; PF.sub.6.sup.-, BF.sub.4.sup.-, CIO.sub.4.sup.-, B(C.sub.6 H.sub.5).sub.4.sup.

Abstract: Polyhydroxylated compounds such as glucose, sucrose, sorbitol, etc. are subjected to a hydrogenolysis reaction at hydrogenolysis conditions which include a temperature in the range of from about 175.degree. to about 250.degree. C. and a pressure in the range of from about 10 to about 2000 pounds per square inch in the presence of a catalytic composition of matter. The catalyst comprises a carbonaceous pyropolymer possessing recurring units containing at least carbon and hydrogen atoms which is impregnated with a transition metal. The products which are obtained will include alcohols, acids, ketones, ethers, and hydrocarbons.

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: ##STR1## wherein R.sub.1 and R.sub.2 are equal or different alkyl-, alkoxyalkyl-, or aryl groups, or together form a ring; R.sub.3 is an allyl or benzyl radical; and R.sub.4 and R.sub.5 represent hydrogen, alkyl, alkoxyalkyl, alkenyl or further compounds of the formula II: ##STR2## wherein R.sub.1, R.sub.2, R.sub.4 and R.sub.5 have the meaning indicated above and R.sub.6 stands for hydrogen or methyl or to compounds which are modified by the addition of hydrogen to at least one olefinic or carbonylic double bond of compounds of the general formula I or II. The invention also relates to a process for preparing the new compounds. The compounds of the general formula II are obtained by thermal treatment of a selection of compounds of formula I, for which R.sub.3 stands for the allyl or methallyl radical. The compounds according to the invention are used as fragrant and flavoring substances.

Abstract: A process for preparing cyclopentenone derivatives represented by the formula: ##STR1## wherein R.sub.1 is methyl or ethyl, and R.sub.2 is hydrogen, methyl or acetyl, characterized in that a 1,4-diketone derivative represented by the formula:R.sub.1 COCH.sub.2 CH.sub.2 COCH.sub.2 OR.sub.2wherein R.sub.1 and R.sub.2 are as defined above is cyclized in the presence of a basic catalyst.

Abstract: A method of producing a 4-hydroxycyclopentenone represented by the formula, ##STR1## wherein R.sub.1 is an alkyl, alkenyl, alkynyl, cycloalkyl, thienyl, phenyl, p-methylbenzyl or benzyl group and R.sub.2 is an alkyl, alkenyl or alkynyl group having 6 or less carbon atoms, which comprises reacting a furylcarbinol compound of the formula, ##STR2## wherein R.sub.1 is as defined above, in the presence of an acid in a mixed solvent of water and an organic solvent, to obtain a cyclopentenone compound of the formula, ##STR3## wherein R.sub.1 is as defined above; reacting the cyclopentenone compound in the presence of an oxidizing agent to obtain a cyclopentendione compound of the formula, ##STR4## wherein R.sub.1 is a defined above; reacting the cyclopentendione compound with a Grignard reagent of the formula,R.sub.2 MgXwherein R.sub.2 is as defined above and X is chlorine, bromine or iodine atom, to obtain an oxocyclopentene compound of the formula, ##STR5## wherein R.sub.1 and R.sub.

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: The preparation of racemic 1R, 4R, 5R-5-(4', 8'-dimethyl-5'-hydroxy-7'-nonenyl)-5-methyl-8-oxabicyclo[3.2.1]-octane-1-a cetic acid is described. The cycloheptane compounds are active uteroevacuant agents.

Abstract: The present invention relates to a novel method for producing cyclopentenolone of the formula (I), ##STR1## which is a useful intermediate for producing agricultural chemicals, which comprises reacting an acetonedicarboxylic ester of the formula (VII), ##STR2## wherein R is a C.sub.1 -C.sub.6 alkyl group, with 2-propynyl chloride in the presence of magnesium alkoxide and in the presence of alkali iodide to obtain novel mono-(2-propynyl)-substituted acetonedicarboxylic ester of the formula (VI), ##STR3## wherein R is as defined above; hydrolyzing the mono-(2-propynyl)-substituted acetonedicarboxylic ester of the formula (VI) under alkaline conditions with an alkali and then reacting the hydrolyzed product with methylglyoxal of the formula, ##STR4## to obtain novel .gamma.-diketone of the formula (V), ##STR5## and ring-closing the .gamma.-diketone of the formula (V) under alkaline condition.

Abstract: Prostaglandin analogs and process for the preparation thereof as precursors or the synthesis of oligomeric mixtures exhibiting biological activity for protection of oxidative phosphorylation of degraded mitochondria. The analogs have the general formula: ##STR1## synthesized by O-alkylating a 2-alkylcyclopentane-1,3-dione to form an enol ether, reacting the ether with CH.sub.2 .dbd.CHMgBr to form a vinyl, oxidizing the vinyl with OsO.sub.4 and NaIO.sub.4 to form an aldehyde, and reacting the aldehyde with a sodium salt of dimethyl (2-oxoalkyl)phosphonate.

Abstract: A process for the preparation of an electrically conductive polyene, wherein a polyene which contains one or more chain members of the formula where R is hydrogen or methyl, and which contains a total of not less than seven aliphatic double bonds, is treated, in the absence of moisture and of oxygen, with a strong Lewis acid having a pk.sub.a of from -10 to +4, or with an alkali metal.

Abstract: A process for the preparation of dihalovinyl compounds of the formula ##STR1## wherein each Hal is fluorine, chlorine or bromine, R.sup.1 is an optionally substituted hydrocarbyl group, R.sup.2 is a methyl group or a hydrogen atom, or R.sup.1 and R.sup.2 together with the carbon atom to which they are attached form cycloalkylidene group, which process comprises treating a trihalo compound of the formula ##STR2## wherein Hal, R.sup.1 and R.sup.2 have the above meanings and R.sup.3 is a hydrogen atom or ##STR3## in which M is an alkali atom, with PHal.sub.3.