Reaction between benzaldehyde and methyl α- benzylsulfonylacetate furnishes methyl (E)-α- benzylsulfonyl-β-phenylacrylate as the exclusive Knoevenagel adduct. The related condensations between α-benzylsulfonylacetonitrile and paraformaldehyde furnish trans-1-benzylsulfonyl-2-phenylcyclopropane-1-carbonitrile in modest yields. These product structures are established by X-ray crystallographic analysis. Phenylsulfene is ruled out as an intermediate in the formation of the cyclopropane.