Mechanisms for the alkaline hydrolysis of dibromodifluoromethane-alkene adducts to alpha,beta-unsaturated carboxylates

Alternative mechanisms for the title reactions are probed. The previously-r eported pathway involving double dehydrobromination to a difluorodiene is o perative in at least one case, but this route is specifically excluded for systems that cannot dehydrobrominate to dienes yet still yield carboxylates upon alkaline hydrolysis. Although S(N)2, S(N)1, S(RN)1, and monoeliminati on-addition processes appear formally possible, an S(N)2' mechanism is impl icated by studies on model compounds. (C) 2000 Elsevier Science S.A. All ri ghts reserved.