Mechanisms for the alkaline hydrolysis of dibromodifluoromethane-alkene adducts to α,β-unsaturated carboxylates

Alternative mechanisms for the title reactions are probed. The previously-reported pathway involving double dehydrobromination to a difluorodiene is operative 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 SN2, SN1, SRN1, and monoelimination–addition processes appear formally possible, an SN2′ mechanism is implicated by studies on model compounds.