Studies in terpenoid biosynthesis. Part 25. The fate of the mevalonoid hydrogen atoms in the biosynthesis of the sesquiterpenoid, dihydrobotrydial

Abstract

The ¹H n.m.r. spectrum of dihydrobotrydial and its ethyl ether were assigned. The number of mevalonoid labels that were incorporated into dihydrobotrydial by the fungus, Botrytis cinerea, were determined from ³H : ¹⁴C ratio studies whilst the location of the labels was defined by ²H n.m.r. methods. A 1,3-hydrogen shift occurs during the cyclization and ¹⁸O studies show that the 9-hydroxy-group arises from water.