PHOTOOXYGENATION OF 2-ALKENYL SUBSTITUTED CHIRAL OXAZOLINES - STEREOCHEMICAL EVIDENCE FAVORING THE CIS EFFECT IN THE REGIOSELECTIVE ENE REACTION OF SINGLET OXYGEN WITH ALPHA,BETA-UNSATURATED CARBONYL DERIVATIVES

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.