Stereoselective syntheses of (+)-goniotriol, (+)-8-acetylgoniotriol, (+)-goniodiol, (+)-9-deoxygoniopypyrone, (+)-altholactone, and (-)-goniofupyrone

The gamma-lactone intermediate (-)-7, derived from (+)-tricarbonyl(eta(6)-o-(trimethylsilyl)benzaldehyde)chromium (O) complex, was efficiently converted into the corresponding delta-lactone intermediate (-)-11. This second intermediate has been shown to be a versatile compound for stereoselective syntheses of natural styryllactones possessing a six-membered lactone moiety, isolated from Goniothalamus giganteus, by transforming it into (+)-goniotriol, (+)-8-acetylgoniotriol, (+)-goniodiol, (+)-9-deoxygoniopypyrone, (+)-altholactone, and (-)-goniofupyrone.