A direct route to angularly substituted hydrindanes. Formal synthesis of bakkenolide-A and synthesis of an advanced intermediate to umbellactal

A direct route for the synthesis of highly functionalized angularly substituted hydrindanes has been developed. The key step involves RO–RCM of an appropriately functionalized norbornene derivative. The hydrindane derivative obtained in this way has been used to accomplish a formal synthesis of bakkenolide-A. This protocol has also been extended for the synthesis of an advanced intermediate to the synthesis of the diterpene umbellactal.