A short, convergent synthesis of aristolindiquinone

Abstract

Aristolindiquinone, 2,5-dihydroxy-3,8-dimethyl-1,4-naphthoquinone 1, is synthesised by the regiochemical addition of 1-methoxy-1-trimethylsiloxypenta-1,3-diene 2 to 5-bromo-2-methoxy-3-methyl-1,4-benzoquinone 3. The regioisomer 2,8-dihydroxy-3,5-dimethyl-1,4-naphthoquinone 4 is prepared by reaction of the same diene 2 with 2-methoxy-3-methyl-1,4-benzoquinone 11. The former reaction readily provided sufficient quantities of aristolindiquinone 1 for biological evaluation for fertility regulation in rats, for which purpose it was found to be inactive.