Efficient Entry to Tetrahydropyridines: Addition of Enol Ethers to Allenesulfonamides Involving a Novel 1,3-Sulfonyl Shift

Abstract

Heating at 70–100°C is all that is needed to induce a novel 1,3-sulfonyl shift in the reaction of N-allenesulfonamides with enol ethers [Eq. (a)]. Tetrahydropyridine derivatives are obtained in excellent yields and with high stereoselectivities.