The first highly asymmetric pummerer-type reaction in chiral acyclic sulfoxides: Chemistry of O-silylated ketene acetals
作者:Yasuyuki Kita、Norio Shibata、Naoki Yoshida
DOI:10.1016/s0040-4039(00)60616-0
日期:1993.6
The chiral sulfoxides (4) were reacted with O-silylatedketeneacetal (2) in acetonitrile to give the corresponding α-siloxysulfides (5) in high degree of stereochemistry and high yields.
optically active cyanomethyl aryl sulfoxides with aceticanhydride gave the corresponding α-acetoxy sulfides which were induced with a partial asymmetry nearly 30% at α-carbon, while the 18O-label of the original sulfoxides was retained in more than 85% in the resulting ester, the Pummerer reaction product. Kinetic experiments with cyanomethyl (p-substituted phenyl) sulfoxides and α,α-dideuterated cyanomethyl
Bakers' yeast oxidation of methyl para-tolylsuifide: Synthesis of a chiral intermediate in the preparation of the mevinic acid-type hypocholestemic agents
作者:Jenny Tang、Ian Brackenridge、Stanley M. Roberts、Jean Beecher、Andrew J. Willetts
DOI:10.1016/0040-4020(95)00819-t
日期:1995.11
The use of (R)-methyl para-tolylsulfoxide as a chiral auxiliary in a novel synthesis of a key intermediate en route to mevinic acid-type hypocholestemic agents is described. The synthesis is short and simple consisting of eight steps to yield enantiomerically pure beta-silyloxy-delta-lactone. The chiral sulfoxide used in the synthesis was obtained via a straightforward biooxidation of methyl paratolylsulfide using bakers' yeast (Saccharomyces cerevisiae NCYC 73). The biotransformation involves the use of whole cells and affords the sulfoxide in good yield and with high stereoselectivity.
Kita, Yasuyuki; Shibata, Norio; Yoshida, Naoki, Journal of the Chemical Society. Perkin transactions I, 1994, # 22, p. 3335 - 3342