Chemistry of the Podocarpaceae. XVIII. α-Tetralones derived from podocarpic acid

Abstract

Brief treatment of a variety of derivatives of podocarpic acid (I) with bromine in ether, preferably containing a free-radical initiator such as benzoyl peroxide, gave after hydrolysis the corresponding 7-oxo compound in moderate to good yield. This reaction occurred both in compounds containing a methoxyl group at C12 (11) and in one without (XIX). Alkyl groups attached to the aromatic ring were unreactive. In suitable cases, normal polar bromination was also observed.