A simple method for the synthesis of both cis-2-vinylaziridines and 3-pyrrolines from common intermediate (Z)-4-(N-arylsulfonyl) amino-4-alkylbut-2-en-1-ols, is described. Palladium (0)-catalyzed reactions of methyl carbonates of the N-protected (Z)-4-amino-4- alkylbut-2-en-1-ols yield predominantly cis-3-alkyl-2-vinylaziridines. Alternatively, upon exposure to sodium hydride, methanesulfonates derived from N-protected (Z)-4-amino-4- ...