Chemistry of the Podocarpaceae. LXIV. Studies in the ambergris odorant field

Abstract

The cyclic ethers 17-nor-16-oxa-l3β-kaurane (8) and 15,16-epoxy-17-nor-15,16-seco-8β,13β-kaurane (11) have been prepared from 13 β-kaur-15-ene ('isophyllocladene')(1) and 13 β-kaur-16-ene ('phyllocladene') (2), respectively. The derivative (8), but not (11), possesses an ambergris-type odour. Preparation of the 8 β,12-epoxides (30),(31),(33) and (34) from 12-hydroxypodocarpa-8,11,13-trien-19-oic acid ('podocarpic acid') (3) indicates that substitution of the 4β-methyl group destroys their potentially odoriferous nature. An attempt to prepare epimers of the C8 demethyl analogue of the known ambergris-type odorant (45) is reported; a mixture of the C13 epimers of (45) is readily prepared from the unsaturated ketone (41).