Abstract
-
TiCl4 and TiBr4 rapidly transform cyclopropenylmethyl acetates to (E)-halodienes via ring-opening to allyl-vinyl cations. DFT calculations suggest that the regioselectivity of the halogenation of this cationic intermediate by [TiX4OAc]− is under thermodynamic control, while the stereoselectivity is governed by kinetics.