Structure revision of pilidiostigmin from the leaves of Pilidiostigma glabrum

Abstract

The structure of the dimeric phloroglucinol natural product pilidiostigmin, previously reported from the leaves of the Australian rainforest plant Pilidiostigma glabrum, has been revised based on reinterpretation of the spectroscopic data. Pilidiostigmin is an oxidised diacyldibenzofuran. ROESY exchange correlations indicate that pilidiostigmin occurs in solution as an almost equimolar mixture of two interconverting 3-hydroxycyclohexenone tautomers.