Richard A. Bunce* and Jeffrey C. Allison' ... Department of Chemistry, Oklahoma State University Stillwater, Oklahoma 74078-3071 ... Abstract. A tandem S,ZMichael addition sequence has been developed for the preparation of N-(4-methylbenzenesulfonyl)- pyrrolidines and piperidines bearing functionalized side chains at C-2. ... Introduction. Five- and six-membered nitrogen heterocycles are common structural units in natural products chemistry,' and the development of new ...