Abstract Reaction of certain geometrically defined 1, 1-dioxy-4-alkyl-and-4, 4-dialkyl- substituted buta-1, 3-dienes with halogenated quinones does not involve Diels–Alder or Michael addition chemistry. Instead, rapid competitive oxidation of the dienes to give 2, 4- dienoate esters was observed. This new reaction involves strong spatial association between diene and quinone, hydrogen being transferred specifically from the (4E)-alkyl ...
