The Effects of Various Additives on the Regioselectivity of the Reactions of Ally! Dithiocarbamate with Aldehydes

Abstract

The effects of various additives on the regioselectivity in the reactions of ally! dithiocarbamate with aldehydes were examined. The lithium salt of allyl dithiocarbamate reacts with aldehydes in the 'absence of an additive to give γ-adducts exclusively. However, the reactions in the presence of some additives, especially of Ti(OPrⁱ)₄, afford α-adducts in a regioselective manner. These reactions are explained by assuming a 6-membered chair form transition state, involving a titanium atom.