Synthesis and properties of benzoannelated 6-(1,3-dithiolan-2-yliden)-2,4-cyclohexadien-1-ones

Abstract

A general route to push-pull stabilized quinone methides starting from the corresponding phenols and proceeding viaalkylation of aromatic hydroxy dithiocarboxylates has been used to synthesize the 1-oxo-2-(1,3-dithiolan-2-yliden)-1,2-dihydronaphthalene (V) and 9-oxo-10-(1,3-dithiolan-2-ylide)-9,10-dihydrophenanthrene (VI). In the case of α-naphthole, the reaction leads to a mixture of isomers with little preference shown for para vs ortho. The structures of the compounds are elucidated by their 1H-NMR spectra.