Dunnione and related naphthoquinones. I. The isodunnione series

Abstract

Synthesis of hydroxyhydroisodunniol proves the structure of this compound, and of α- and β-isodunnione. Experiments on the synthesis of isodunniol do not support the structure previously assigned to it, and the alternative formula, 2-hydroxy-3-(1,2-dimethylally1)-1,4-naphthoquinone, is suggested. Evidence is presented for the occurrence of steric inhibition of resonance in certain 2-hydroxy-3-alkylene-1,4-naphthoquinones. Synthetic homologues of the lapachol and dunnione series are described.