SYNTHETIC STUDIES ON INGENOL - BRIDGEHEAD ENOLATE REACTIVITY AND ABC RING ASSEMBLY

The architecturally complex and highly oxygenated diterpene ingenol (la) has been the subject of intense synthetic investigation in recent years.1 The relatively unusual bicyclo[4.4.1] undecane skeleton coupled with the stereochemical intricacies and high level of oxygenation which characterize this compound make for a particularly intriguing target for testing the prowess of modern organic synthesis. The importance of this substance is further magnified by the recognition that numerous fatty acid ester derivatives at the C3 hydroxyl group are potent tumor-promoting species.2 Recent work has suggested that the initial mode of action of these compounds may be associated with binding to, and activation of, protein kinase C.3. © 1990, American Chemical Society. All rights reserved.