Consecutive Aminolithiation–Carbolithiation of a Linear Aminoalkene Bearing Terminal Vinyl Sulfide Moiety to Give Hydro­indolizine

Abstract

Aminolithiation–carbolithiation tandem cyclization of an aminoalkene bearing vinyl sulfide moiety proceeded smoothly using stoichiometric amounts of BuLi. Both aminolithiation and carbo­lithiation were in equilibrium at room temperature, and the stereochemistry of the cyclization was thermodynamically controlled. At –78 °C the reaction was kinetically controlled and the cyclized product, 1,2-disubstituted octahydroindolizine, was obtained with good dia­stereoselectivity.