Chemical studies of marine invertebrates. Part 46. Confirmation of the molecular structure of sigmosceptrellin-B by X-ray diffraction analysis

Abstract

The structure of sigmosceptrellin-B (3), a norsesterterpene peroxide isolated from the sponge Sigmosceptrella laevis, had previously been proposed on the basis of chemical correlations. This structure has now been independently confirmed by an X-ray diffraction analysis on the crystalline derivative (1S,4aR,5S,6R,8aR)-1-hydroxymethyl-5-{2-[(3R,6S)-3-(1R)-(2-hydroxy-1-methylethyl)-6-methyl-1,2-dioxan-6-yl]ethyl}-5,6,8a-trimethylbicyclo[4.4.0]decan-1-ol (6). This paper discusses the conformational parameters of the 1,2-dioxan ring of (6).