Insect moulting hormones: Crustecdysone (20-hydroxyecdysone) from Podocarpus elatus

The insect moulting hormone crustecdysone has been isolated from the Australian brown pine, Podocarpus elatus R.Br., and detected in a number of other Podocarpus species from various parts of the world. A series of acetates and acetonides of crustecdysone has been prepared, and the mass and nuclear magnetic resonance spectra of these compounds analysed. A simple micro method of measuring the rate of acetylation of hydroxy groups in steroids has been developed to determine the steric environment of these groups.