Cyclic Sulfamidates as Precursors to Alkylidene Pyrrolidines and Piperidines

The reaction of the dienolate of ethyl acetoacetate (and related dienolates) with a range of 1,2- and 1,3-cyclic sulfamidates provides an entry to substituted and enantiopure alkylidenated pyrrolidines and piperidines. These heterocycles function as convenient precursors to heterocyclic beta-amino acid derivatives.