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.