Minor and trace sterols in marine invertebrates 55. The isolation, structure elucidation and synthesis of ergosta-5, 24(28), 25-trien-3 beta-ol.

The isolation, structure determination and synthesis of ergosta-5, 24(28), 25-trien-3 beta-ol, as well as the synthesis of its 28-14C analog--a possible biosynthetic precursor of several marine sterols--is described.