Formal total synthesis of trichodiene via skeletal rearrangement of regioselective photochemical [2 + 2] cycloadducts from cyclohexene derivatives

Abstract

A formal total synthesis of trichodiene 1 is accomplished via the photochemical [2 + 2] cycloaddition of 3-methylcyclohex-2-enone with methyl cyclohex-1-enecarboxylate to give methyl (1α, 2β, 7β, 8α)-2-methyl-6-oxotricyclo[6.4.0.0^2,7]dodecan-1-carboxylate, and its skeletal rearrangement to give a tricyclo[6.4.0.0^2,6]dodecene derivative. Cleavage of the central five-membered ring of the tricyclo[6.4.0.0^2,6]dodecene and modification of functional groups leads to the synthesis of trichodiene 1.