Representative (Z)-2-(bromomethyl)-2-alkenoates were easily prepared in high yield by treating α-methylene-β-hydroxyesters (Morita-Baylis-Hillman adducts) with LiBr/H2SO4 in acetonitrile at room temperature. Besides the tolerance to many diverse functional groups, this new methodology employs inexpensive reagents and avoids the use of HBr.
Morita-Baylis-Hillman reaction; α-methylene-β-hydroxyesters; (Z)-allylic bromides; N-allyl acetamides