Biomimetic radical ring expansion and aromatisation; a model for the biogenesis of natural ring-D aromatic steroids

Abstract

Photolysis of the thiohydroxamate 7 generated the carbon radical 9, which rearranged and aromatised to the methyltetralin 8, providing a model for the biogenesis of the insect antifeedant steroid nic-1 1 from the conventional C/D precursor nic-3 2: photolysis of the isomeric thiohydroxamate 13 gave both methyltetralins 8 and 14, through an unusual rearrangement sequence, possibly involving the benzvalene related radical 17.