BAKERS-YEAST OXIDATION OF METHYL PARA-TOLYLSULFIDE - SYNTHESIS OF A CHIRAL INTERMEDIATE IN THE PREPARATION OF THE MEVINIC ACID-TYPE HYPOCHOLESTEMIC AGENTS

The use of (R)-methyl para-tolylsulfoxide as a chiral auxiliary in a n ovel synthesis of a key intermediate en route to mevinic acid-type hyp ocholestemic agents is described. The synthesis is short and simple co nsisting of eight steps to yield enantiomerically pure beta-silyloxy-d elta-lactone. The chiral sulfoxide used in the synthesis was obtained via a straightforward biooxidation of methyl paratolylsulfide using ba kers' yeast (Saccharomyces cerevisiae NCYC 73). The biotransformation involves the use of whole cells and affords the sulfoxide in good yiel d and with high stereoselectivity.