An ester enolate rearrangement/silicon mediated fragmentation cascade was used to convert 7 and 8 into the alcohol 9.The alcohol 9 was converted into the allylic alcohol 12 andthen to the ester 14. A further ester enolate rearrangementfurnished the stereochemical identity of galbonolide B 1.Base mediated macrocyclization of the acetate ester 16followed by base mediated alkylation and acetal deprotectiongave galbonolide B 1.
