CYCLOPENTYL-ALKANOIC ACIDS

1,236,227. Substituted cyclopentanealkanoic acids. CIBA-GEIGY A.G. 20 May, 1968 [22 May, 1967; 12 Feb., 1968], No. 50088/69. Divided out of 1,236,226. Heading C2C. [Also in Division C3] Novel compounds of Formula (I) and their 1-α epimers, esters, ethers and salts wherein X is O or a group of formula R 1 .O.N = in which R 1 is H, C 1-7 alkyl, C 2-7 alkenyl, C 3-6 cycloalkyl, (C 3-6 )-cycloalkyl-(C 1-4 )-alkyl, halogeno-(C 1-7 )-alkyl, R-(C 1-7 )-alkyl where R is phenyl, (C 1-7 alkyl)-phenyl, (C 1-7 alkoxy)- phenyl, (C 1-7 alkylenedioxy)-phenyl, halogenophenyl, trifluoromethylphenyl, nitrophenyl or di-(C 1-7 alkyl)-aminophenyl, are prepared by reducing the C=C double bond in the novel compound of Formula (Ia) or in its novel esters, ethers or salts, and optionally reacting a resulting ketone with a compound of formula H 2 NOR 1 and/or if desired, epimerizing a resulting compound. 2 - (6 - Methoxycarbonylhexyl)- 3 - oxo - 5 - acetoxy - 1 - cyclopentene carboxylic acid methyl ester is prepared by action of silver acetate in acetic acid or the reaction product of N-bromosuccinimide and 2-(6-methoxycarbonylhexyl)-3- oxo - 1 - cyclopentene carboxylic acid methyl ester obtained by esterification of the corresponding dicarboxylic acid which in turn is obtained by hydrolysis of its diethyl ester prepared by treating the enol acetate of 2-(6-ethoxycarbonylhexyl) - 3 - oxo - cyclopentane carboxylic acid ethyl ester with bromine, the said enol acetate being obtained by treatment with isopropenyl acetate of the aforesaid ester. 2 - (6 - Ethoxycarbonyhexyl) - 3 - oxo - cyclopentane carboxylic acid ethyl ester is prepared by cyclization of 1,3,4,10-decanetetracarboxylic acid tetraethyl ester obtained by esterification of the free acid obtained by hydrolysis and decarboxylation of 1,3-dicyano-3,4,10-decanetricarboxylic acid triethyl ester prepared by reaction of acrylonitrile and triethyl α-cyano-#-carboxysebacate prepared by reaction of diethyl α- bromoazelate and ethyl cyanoacetate.