RCN t Bu2SnS (2) involves nucleophilic attack by sulfur on the Sn= O function to give reactive intermediate 1, where X= H. It is known, however, that dibutyltin oxide and methanol rapidly forms dibuty1dimetho~ ytin. l~ It is therefore probable that attack by sulfur at the tin atom also involves this dimethoxytin derivative to give intermediate 1, where X= Me. Either form of 1 can undergo a/3 elimination (presumably by the El mechanism illustrated) to ...
