A stereocontrolled Synthesis of dl-Biflora-4,10(19),15-triene

Article abstract of DOI:10.1021/jo00371a020

The stereoselective synthesis of dl-biflora-4,10(19),15-triene (1), a bicyclic diterpene component of the defense secretion of termite soldiers (Cubitermes umbratus), makes use of the regioselective Ireland-Claisen rearrangement of the Z-enolates of esters of 2,5-disubstituted 1,4-dien-3-ols.The synthetic scheme links the dienol Ireland-Claisen rearrangement with an intramolecular Diels-Alder closure; this strategy allows introduction of the four contiguous chiral centers with the desired relative stereochemistry.