Patent ID: 7153983

Claim:
A process for preparing optically enriched substituted R(+)β-benzyl-γ-butyrolactones having the general formula wherein, R 1 and R 2 independently represent the following groups R 1 ═R 2 ═H, OH, —OC n H 2n+1 (n=1 to 8), NH 2 , or CF 3 R 1 and R 2 together represent —O(CH 2 ) m O— where m=2 to 4 and said process comprises the steps of: a) reacting alkoxybenzene having the following formula wherein R 1 and R 2 are as mentioned above, with succinic anhydride, a Lewis acid in an inert solvent at a temperature in the range of 0–5° C., b) esterifying the product 4-keto-4-phenyl-butyric acid having the following formula obtained in step (a) with an alcohol and an acid to yield 4-keto-4-phenyl butyrate having the following formula c) reducing the keto group of the compound having the formula obtained in step (b) with a metal hydride catalyst in the presence of hydrogen gas to yield the corresponding secondary alcohol 4-hydroxy-4-phenyl butyrate having the following formula d) formylating the compound having the formula obtained in step (c) with an equimolar mixture of phosphoryl choloride and dimethyl formamide to produce at a temperature in the range of about −5° C. to 50° C. for about 36 hours 4-phenyl-3-formul-3ene-butrylate having the following formula e) catalyzing the unsaturated formyl ester having formula obtained in step (d) with a yeast selected from the group consisting of Baker's yeast, Candida spp. or Pichia spp. to obtain an optically enriched R(−)dihydro primary alcohol having the following formula at a temperature of about 30° C. for about 50 hours or to obtain a compound having said general formula, wherein R 2 substituent is H; and f) cyclizing the dihydro primary alcohol having the formula from step (e) with an acid at a temperature of about 70° C. for 20 minutes to produce substituted R(+)β-benzyl-γ-butyrolactone having said general formula.