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Paper | Special issue | Vol 39, No. 2, 1994, pp.527-552
Published online, 1st January, 1970
DOI: 10.3987/COM-94-S(B)34
A Microbial Lipase Based Stereoselective Synthesis of (d)-α-Tocopherol from (R)-Citronellal and (S)-(6-Hydroxy-2,5,7,8-tetramethylchroman-2-yl)acetic Acid

David L. Coffen,* Noal Cohen, Anthony M. Pico, Rudolph Schmid, Mark J. Sebastian, and Frederick Wong

*Roche Research Center Hoffmann-La roche, Inc., Nutley, New Jersey 07110, U.S.A.

Abstract

A new synthesis of natural vitamin E (2R,4’R,8’R)-α-tocopherol) based on (R)-citronellal and (S)-(6-hydroxy-2,5,7,8-tetramethylchroman-2-yl)acetic described. The citronellal is elaborated into an optically pure C13 allylic carbonate using a lipase catalyzed kinetic resolution to control the new chiral center. Palladium catalyzed coupling of this C13 carbonate with either a β-ketoester or β-ketosulphone derived from the chromanylacetic acid completes the assembly of the α-tocopherol skeleton. Appropriate functional group modifications are used to complete the synthesis.