The Constituents of Marine Sponges. VII. The Absolute Stereochemistry of Aplyroseol-1.

Abstract

The absolute stereochemistry of aplyroseol-1 (1), a diterpenoid isolated from Aplysillarosea Barrois, has been established as (5S; 7R; 8S; 9R; 10S; 13R; 14R; 15R) by determining the crystal structure of the p-bromobenzoyl derivative (3) by X-ray diffraction methods. The structure was refined to a residual of 0·032 for 1451 independent observed reflections. The crystals are monoclinic, space group P 2₁, a 6·668(8), b 20·04(1), c 10·974(3) Å, β 98·04(7)°.