Synthesis of Enantioenriched α‐(Hydroxyalkyl)‐tri‐<i>n</i>‐butylstannanes

Abstract

Li and Mg are pesky: A catalytic asymmetric synthesis of α-(hydroxyalkyl)-tri-n-butylstannanes (1) in good to excellent yields and enantioselectivities was achieved (see scheme; PG=protecting group; L*=chiral ligand). Compound 1 was isolated as an ester or thiocarbamate, and the reagent was prepared from equimolar amounts of nBu3SnH and Et2Zn in dimethoxyethane. Conditions employing lithium or magnesium ions suppress enantioselectivity.