NOVELTY - Racemization of (R)-3-cyano-5-methylhexanoic acid to obtain (SR)-3-cyano-5-methylhexanoic acid, comprises: (a) conversion of (R)-3-cyano-5-methylhexanoic acid into 3-cyano-5-methyl-hexanoic acid through esterification reaction, such as "mixed-anhydride" technique employing ethyl chloroformate/triethylamine with ethanol or through Steglich esterification or acid catalyzed esterification or esterification by any other conventional methods; and (b) treatment of 3-cyano-5-methyl-hexanoic acid with alkali metal alkoxides in a mixture of protic and aprotic polar solvents.    USE - The process is useful for racemization of (R)-3-cyano-5-methylhexanoic acid to obtain (SR)-3-cyano-5-methylhexanoic acid (claimed), which is useful as intermediate for converting (S)-pregabalin.    ADVANTAGE - The process provides racemization of (R)-3-cyano-5-methylhexanoic acid to obtain (SR)-3-cyano-5-methylhexanoic acid in an economical, industrial and environmentally friendly manner.    DETAILED DESCRIPTION - Racemization of (R)-3-cyano-5-methylhexanoic acid to obtain (SR)-3-cyano-5-methylhexanoic acid, comprises: (a) conversion of (R)-3-cyano-5-methylhexanoic acid into 3-cyano-5-methyl-hexanoic acid through esterification reaction, such as "mixed-anhydride" technique employing ethyl chloroformate/triethylamine with ethanol or through Steglich esterification or acid catalyzed esterification or esterification by any other conventional methods; and (b) treatment of 3-cyano-5-methyl-hexanoic acid with alkali metal alkoxides in a mixture of protic and aprotic polar solvents, where aprotic polar solvent is dimethyl sulfoxide, dimethylformamide, dimethoxyethane, 2-methyl tetrahydrofuran, methyl tert-butyl ether and N-methyl-2-pyrrolidone, preferably dimethyl sulfoxide and methyl tert-butyl ether, and protic polar solvent is methanol, ethanol, propanol and butanol. An INDEPENDENT CLAIM is included for a process for conversion of 3-cyano-5-methyl-hexanoic acid to (SR)-3-cyano-5-methylhexanoic acid comprising treatment of 3-cyano-5-methyl-hexanoic acid with alkali metal alkoxides in a mixture of protic and aprotic polar solvents.