A SIMPLE AND HIGHLY STEREOSELECTIVE ROUTE TO (+/-)-PODOCARPIC ACID

The ring C aromatic resin acids form an important group of naturally occurring diterpenoids, which are broadly classified into two types, viz., abietane and podocarpane differing in the configuration of 4-C02H (a in the former and β in the latter in the natural 5a series). Quite a number of syntheses of both the stereoisomeric forms have been reported over the last few decades.1Of the various methods, the acid-catalyzed intramolecular cycloalkylation route presents a simple and convergent synthesis of these aromatic resin acids, particularly those related to a po-docarpic acid ring system2. © 1990, American Chemical Society. All rights reserved.