Minor and trace sterols in marine invertebrates. 27. Isolation, structure elucidation, and partial synthesis of 25-methylxestosterol, a new sterol arising from quadruple …

LN Li, U Sjoestrand, C Djerassi

Index: Li, Lian Niang; Sjoestrand, Ulf; Djerassi, Carl Journal of Organic Chemistry, 1981 , vol. 46, # 19 p. 3867 - 3870

Full Text: HTML

Citation Number: 26

Abstract

A novel Cal sterol, 25-methylxestosterol, resulting from quadruple biomethylation in the side chain has been isolated as a trace constituent of the sterol fraction from a Caribbean sponge (Xestospongia sp.). Ita structure (1, 24-methylene-25, 26, 27-trimethylcholesterol) has been elucidated by spectroscopic methods and confirmed by partial synthesis. A biosynthetic route leading to 1 is proposed that is consistent with the hypothesis of stepwise ...