Oxidative cyclization of tertiary pentenol derivatives forming 2,5,5-trisubstituted THF rings and the total synthesis of cyclocapitelline

The synthesis of 2,5,5-trisubstituted tetrahydrofuran rings was accomplished via the Mukaiyama aerobic oxidative cyclization of tertiary 5-pentenols employing the Co(nmp)2catalyst. A variety of THFs were formed in moderate to good yield and diastereoselectivity. The method developed herein was successfully applied to an enantioselective total synthesis of cyclocapitelline