Conjugate reduction of aryl acrylates with tributyltin hydride in the presence of magnesium bromide diethyl etherate

The conjugate reduction of aryl acrylates performed with tributyltin hydride in the presence of magnesium bromide diethyl etherate in dichloromethane gave the corresponding saturated esters in moderate to high yields. The reduction of α-methylene-γ-benzyloxycarboxylic acid esters proceeded syn-selectively, but α-methylene-β-oxycarboxylic acid esters afforded reductive elimination products under the reaction conditions.