Patent ID: 8399655

Claim:
A process for producing an optically active compound of formula I or formula II: wherein: R 1 is H, C 1-6 alkyl, C 6-12 aryl, C 6-12 arylalkyl, (CO)C 1-6 alkyl, (CO)O—C 1-6 alkyl, (CO)C 6-12 aryl, or (CO)C 6-12 arylalkyl; R 2 is H, C 1-6 alkyl or CO—R 5 ; R 3 is H, C 1-6 alkyl, bromide, chloride, fluoride, iodide or CF 3 ; and R 5 is H or C 1-6 alkyl; said process comprising: a) reacting a compound of formula III in the cis configuration: with a chiral acid to produce a mixture of two diastereomeric salts, wherein said chiral acid is (1R)-(−)-10-camphorsulfonic acid, (−)-2,3-dibenzoyl-L-tartaric acid, (+)-L-tartaric acid or (−)-L-malic acid; b) recovering a mixture of said two diastereomeric salts containing an excess of one of said two diastereomeric salts; c) converting said one of said two diastereomeric salts into said optically active compound of formula I or formula II.