Reaction of chlorosulphonyl isocyanate with cyclic trienes. Stepwise conjugate addition
Abstract
Chlorosulphonyl isocyanate undergoes dipolar reactions with cyclohepta-1,3,5-triene and cyclo-octa-1,3,5-triene which proceed along a stepwise path culminating in the formation of N-chlorosulphonyl lactams via 1,6-addition; concerted π6s+π2a cycloadditions are discounted.