INITIATED, TERT-BUTYL HYDROPEROXIDE-LOADED, LOW-TEMPERATURE AUTOXIDATION OF ALKENES - A CHEMOSELECTIVE SYNTHESIS OF ALLYLIC HYDROPEROXIDES, ALLOWING ANALYSIS OF THE REGIOSELECTIVITY OF HYDROGEN-ATOM ABSTRACTION FROM SOME UNSYMMETRICALLY SUBSTITUTED SUBSTRATES

A method for the preparation of allylic hydroperoxides is introduced: the method involves the rapid, low-temperature, initiated autoxidation of an alkene (in these instances 1 -methylcyclohexene and the isomeric 4-methyloct-4-enes) ih the presence of tert-butyl hydroperoxide. The success of the method relies upon the selectivity of hydrogen atom abstraction from the substrate by the chain-carrying tert-butylperoxyl radicals, according to the preference for formation of the most stable intermediate allylic radicals, and the reduced rates of chain termination via these same radicals. The method gives a regioselectivity for attack broadly in agreement with predictions from Bolland's rules, and a sufficiently high chemoselectivity for allylic hydroperoxide formation that ready isolation of these products in good yield is achieved.