Structure and Conformation of Two New Dolabellane-Based Diterpenes from Dictyota Sp.

Abstract
Two new dolabellane derivates [3(s)-hydroxy-16-acetoxy-1(B),11(S),12(R)-dolabell-4(E), 8(E), 18-triene and 3(S)-acetoxy-1(R), 11(S), 12(R)-dolabell-4(E), 8(E), 18-trien-16-ale] were isolated from a Dictyota sp. and their structure, including absolute configuration, was determined on the basis of spectral studies and chemical correlations.