Diels–Alder reactions of 4,4-dimethyl-2-cyclohexenones. A direct route to the 4,4-dimethyl-1-decalones

Abstract

Diels–Alder additions to enones 1 and 2, synthetic equivalents of the synthon 3, were studied using a variety of hydrocarbon dienes. The two enones have been shown to be effective and synthetically useful dienophiles. Spectroscopic (especially 1H and 13C magnetic resonance) and chemical techniques were used to define unambiguously the full structures of the adducts. The structures of the various reaction products were used to draw qualitative conclusions about the nature of the transition states involved and the various electronic and steric effects that play a role in the mechanistic course of the Diels–Alder reaction.