Isoaltholactone 1, a furanopyrone natural product belonging to the styryllactone family was isolated from several species of the malasia tree Goniothalamus (G. malayanus, G. montanus and G. tapis). As many styryllactones, isoaltholactone displays important biological activities, including antitumor, antifungal and antibacterial properties.The total synthesis of (-)-isoaltholactone was recently achieved by a synthetic route having as its main feature a highly stereoselective and effective Heck arylation of electron-rich olefins (endocyclic enolether) using arenediazonium tetrafluoroborates. The chiral enolether 3 was prepared in gram quantities from L-glutamic acid following known protocols (5 steps, 55% overall yield). The total synthesis of (-)-isoaltholactone was achieved in 8 steps with an overall yield of 28% from the readily available chiral 5-substituted 2,3-dihydrofuran 3 as depicted below. The strategy permits the synthesis of several other aromatic analogues of isoaltholactone.

synthesis of the chiral endocyclic enolether:

Heck arylation of chiral dihydrofuran 3 with arenediazonium tetrafluoroborates:

completing the synthesis: