Radical cyclization reactions of 4-bromo vinylogous-esters, vinylogous-amides and enones

Abstract

Radicals generated from 4-bromo vinylogous-esters, vinylogous-amides and enones cyclize to a tethered acetylene side-chain preferentially at the γ-position; theoretical calculations of the spin density of the radicals and the relative stability of the radical intermediates are performed to rationalize the experimental observations.