Claims
- 1. Novel process for the preparation of optically enriched substituted R(+)β-benzyl-γ-butyrolactones of the general formula 1 as shown below,
- 2. The process as claimed in step (f) of claim 1, wherein in step (e), the microorganism or enzyme is selected from a group consisting of Baker's yeast, Candida sp., and Pichia sp.
- 3. The process as claimed in claim 1, wherein in step (a) the substituted alkoxybenzene (2) wherein R1 and R2 has the same definition as mentioned earlier, is reacted with succinic anhydride in presence of a Lewis acid selected from a group consisting of anhydrous aluminum trichloride, aluminum tribromide, zinc chloride and boron trifluoride ethereate.
- 4. The process as claimed in claim 3, wherein the Lewis acid used is anhydrous aluminum chloride.
- 5. The process as claimed in claim 1, wherein in step (a) the reaction of succinic anhydride is carried out in an inert organic solvent selected from the group consisting of nitromethane, carbon disulfide and benzene.
- 6. The process as claimed in claim 1, wherein, in step (b) the esterification of (3) is carried out with an alcohol in presence of an acid selected from a group consisting of sulfuric acid, hydrochloric acid and phosphoric acid and alcohol is selected from methanol, ethanol, propanol or mixtures thereof.
- 7. The process as claimed in claim 1, wherein in step (c) the reduction of the keto ester is performed in presence of hydrogen gas using metal catalyst supported on activated charcoal selected from a group consisting of palladium, platinum and nickel.
- 8. The process as claimed in claim 1, wherein in step (c) the reduction of the keto function may also be carried out using metal hydride reagents selected from a group consisting of sodium borohydride, and sodium cyanoborohydride preferably in an aqueous medium or lithium aluminum hydride in an inert organic solvent selected from dimethyl ether, tetrahydrofuran or mixtures thereof.
- 9. The process as claimed in claim 1 wherein in the step (d) formylation of the hydroxy ester (4) is carried out at a temperature ranging between −5° C. to 50° C. using the formylating reagent prepared from equimolar mixture of phosphoryl trichloride and dimethyl formamide.
- 10. The process as claimed in claim 1, wherein in step (e) bioreduction of the prochiral α,β-unsaturated formyl ester (6) is effected by an microorganism or yeast enzyme selected from group consisting of Baker's yeast, Candida species, and Pichia spcies.
- 11. The process as claimed in claim 1, wherein in step (f) the optically enriched hydroxymethyl ester (7) is cyclised with a dilute mineral acid selected from a group consisting of sulfuric acid, hydrochloric acid and phosphoric acid.
Parent Case Info
[0001] The present application claims priority from U.S. Provisional application serial No. 60/366,577 filed on Mar. 25, 2002.
Provisional Applications (1)
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Number |
Date |
Country |
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60366577 |
Mar 2002 |
US |