Enantiopure epoxyvinyl sulfones SS-9a, SS-9b, produced from Jacobsen epoxidation of 2-phenylsulfonyl 1,3-cyclohexa- and cycloheptadiene, are used as a template for the construction of substituted cycloalkenones and as chiral synthetic equivalents of enones a and b. The addition of carbon nucleophiles to SS-9a, SS-9b is high yielding and stereospecific. Enantiopure alpha,beta- and gamma-substituted cycloalkenones are easily constructed using a variety of methods.