Asymmetric hosomi-sakurai reaction of allylsilanes containing arabinose-derived alcohols as chiral auxiliaries

摘要

Five enantiopure allylsilanes 1a-e have been prepared, with arabinose-derived alcohols methyl and benzyl 3,4-0-ispropylidene- and 3,4-0-methylene-β-L-arabinopyranosides as chiral auxiliaries, and subjected to the asymmetric Hosomi-Sakurai reaction. The effect of Lewis acid on the stereochemical outcome of the reaction was investigated, and BF_3 was found to exhibit higher enantioselectivity than that of SnCl_4 or TiCl_4.