Synthesis and 13C nuclear magnetic resonance spectral analysis of some diterpenoids related to the cleistanthane type hydrocarbon isolated from Amphibolisantarctica

Abstract

The synthesis of the cleistanthane-type diterpene 13 (8-β(H), 14-β-ethyl, 13-methylene podocarpane), a dihydro epimer of the natural product 6, is described. By comparison of the 13C nuclear magnetic resonance spectral data of 13 and related compounds with those reported for 6, the stereochemistry of the C-14 side chain of the latter was confirmed.