Photooxygenation of 2-alkenyl substituted chiral oxazolines : Stereochemical evidence favouring the cis effect in the regioselective ene reaction of singlet oxygen with α,β-unsaturated carbonyl derivatives

Abstract

Photooxygenation of the title compound afforded hydroperoxides through regioselective ene reaction of singlet oxygen at the allylic position proximate to the heterocycle; the lack of diastereoselectivity in these ene reactions is taken as evidence against initial [4+2] cycloaddition of the enophile with the heterodiene.