(.alpha.-Haloethyl)silanes optically active at carbon and at silicon. Synthesis and absolute configuration

Abstract

A synthetic sequence that is stereospecific a t silicon was utilized to prepare l-naphthylphenylmethyl(1-chloroethyl)silane, 1, and 1-naphthylphenylmethyl(1-bromoethyl)silane, 2, as a mixture of diastereomers. Crystallization from hexane gave l and 2 as pure diastereomers, the structures of which were determined by X-ray analysis. R,Si= 1-NpPhMeSi 0276-7333/83/23d2-0810$01.50/0 0 1983 American Chemical Society (a-Haloethy1)silanes

Chiral organosilicon compounds in asymmetric synthesis

“…Methylation of 35 gave the ester 36 in 81 % yield and 80% de (Scheme 10). 23 The relatively high asymmetric induction observed in these reactions of a-silylcarbanions suggests that these reactions could be synthetically useful. Even though the silyl moiety had not been removed from the products of these reactions, one can confidently expect that the silyl group can be cleaved oxidatively with high retention of configuration on the basis of known chemistry.24 These reactions can therefore serve as a useful way to synthesize optically active a-hydroxy acids and esters.…”