Synthetic Studies Towards Bridgehead Diprenyl-Substituted Bicyclo[3.3.1]nonane-2,9-diones as Models for Polyprenylated Acylphloroglucinol Construction

摘要

The synthesis of bridgehead diprenylated bicyclo[3.3.1]-nonane-2,9-dione,based on a reductive rearrangement of an enol lactone,is presented.The same target could be reached by a one-step sequence involving Michael addition of 2,6-diprenylcyclohexanone onto acrolein and intramolecular aldol reaction.The first method could be extended to the for-mation of a compound with gem-dimethyl substituents adjacent to the bridgehead position,but the construction of a suitably substituted enol lactone,with a view to polyprenylated acylphloroglucinol elaboration,could not be achieved.