acid were subjected to the reduction with bakers’ yeast. Effects of size and bulkiness as well as hydrophobicity of alcohol moieties of the substrates on the enantioselectivity of the reduction were investigated. The substrates having bulky ester groups gave the (R)-hydroxy esters with high enantioselectivities. A mechanism to alter the stereoselectivity of the reduction is proposed.
SmI2-Induced highly regioselective reduction of α,β-epoxy esters and γ,δ-epoxy-α,β-unsaturated esters. An efficient route to optically active β-hydroxy and δ-hydroxy esters
作者:Kenji Otsubo、Junji Inanaga、Masaru Yamaguchi
DOI:10.1016/s0040-4039(00)96532-8
日期:1987.1
α,β-Epoxy esters were rapidly reduced at room temperature to yield β-hydroxy esters with retention of the configurations at the β-carbon atoms by using SmI2-THF-HMPA system in the presence of N,N-dimethylaminoethanol (DMAE). The conditions were successfully applied to the synthesis of vinylogous δ-hydroxy esters.