Anodic oxidations of electron-rich olefins: radical cation based approaches to the synthesis of bridged bicyclic ring skeletons

The use of intramolecular anodic olefin coupling reactions for building bicyclo[3.2.1]octane ring skeletons has been examined. While simple model systems using bis enol ether substrates readily led to the formation of bicyclic products, application of the reactions to total synthesis efforts were hindered by reactions forming dimethoxy acetal groups at both the terminating and initiating ends of the cyclization reactions. In an effort to solve this problem, ketene acetal based initiating groups have been studied. The use of a ketene dithioacetal group proved especially useful for this purpose.