Intramolecular transacetylation in salvinorins D and E.

Extraction of fresh Salvia divinorum leaves afforded salvinorins E and D as potential biosynthesis precursors of salvinorin A, a major metabolite and a potent hallucinogen. Attempts at HPLC purification of salvinorin E (2) with acetonitrile as a solvent revealed an equilibrium with its regioisomer, salvinorin D (3), in a 3:5 ratio. The presence of both compounds was readily observed in the (1)H NMR spectrum. This spontaneous formation of the mixture of isomers occurs via a dynamic intramolecular transacetylation process.