Timothy J Brocksom | PubMed Health

PubMed2006

Core structure of eremophilanes and bakkanes through niobium catalyzed Diels-Alder reaction: synthesis of (+/-)-bakkenolide A.

A suitable intermediate for the synthesis of eremophilanes and bakkanes was prepared by a highly regioselective and stereoselective one-step synthesis through a niobium catalyzed Diels-Alder reaction. As a demonstration of the versatility of this intermediate, a total synthesis of (+/-)-bakkenolide A is described.

4-Butyrolactone↗

PubMed2002

First comprehensive bakkane approach: stereoselective and efficient dichloroketene-based total syntheses of (+/-)- and (-)-9-acetoxyfukinanolide, (+/-)- and (+)-bakkenolide A, (-)-bakkenolides III, B, C, H, L, V, and X, (+/-)- and (-)-homogynolide A, (+/-)-homogynolide B, and (+/-)-palmosalide C.

Cycloaddition of dichloroketene with dimethylcyclohexenes has been used as the key reaction in an efficient, general approach to the bakkanes. New methods and methodologies that have been developed in this work include spiro beta-methylene-gamma-butyrolactonizations, a vicinal dicarboxylation, an angelic ester preparation, a transesterification, an epoxy ketone double reduction, and a retro aldol-aldol approach to low-energy aldol isomers.

4-Butyrolactone↗