Novel [1,2]- and [2,3]-Wittig Rearrangements of α-Benzyloxy β-CF3-β-lactam Enolates

α-Benzyloxy α-CF3-β-lactams are shown to offer the first examples of the enolate [1,2]- and enolate ortho-[2,3]-Wittig rearrangements which provide a unique entry to the α-benzyl-α-hydroxy lactams and the α-aryl-α-hydroxy lactams, respectively. Both products are potential precursors of new trifluoromethyl isoserines, and the latter is not accessible via the usual alkylation methodology.