Stereoselective total synthesis of bioactive styryllactones (+)-goniofufurone, (+)7-epi-goniofufurone, (+)-goniopypyrone, (+)-goniotriol, (+)-altholactone, and (-)-etharvensin.

Kavirayani R Prasad, Shivajirao L Gholap

Index: J. Org. Chem. 73(1) , 2-11, (2008)

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Abstract

Stereoselective total synthesis of biologically active styryllactones 7-epi-goniofufurone, goniofufurone, goniopypyrone, goniotriol, altholactone, and etharvensin was achieved in high overall yields from a common intermediate derived from d-(-)-tartaric acid. It is based on the utility of a masked tetrol, comprising an alkene tether and four contiguous hydroxy groups. The pivotal reaction sequence involves hydroxy-directed lactonization via the oxidation of alkene, and subsequent elaboration to styryllactones. The masked tetrol was prepared by the extension of gamma-phenyl-gamma-hydroxy butyramide, readily obtained from the bis-dimethylamide of tartaric acid, employing a combination of selective Grignard additions and a stereoselective reduction.