1,7-Electrocyclic substitution by nitrile ylides: the effect on the reaction rate of the nature of the γ,δ-double bond and of aromatic substituents

Abstract

In the competitive cyclisation of 7 to give 9 and 10, all substituents in the 3′ and 4′ positions increased the overall reaction rate relative to that of the 2-phenyl ring; 6-alkenyl and -thienyl groups also reacted faster than the 2-phenyl ring.