Stereoselective Total Synthesis of Bioactive Styryllactones (+)-Goniofufurone, (+)7-<i>epi</i>-Goniofufurone, (+)-Goniopypyrone, (+)-Goniotriol, (+)-Altholactone, and (−)-Etharvensin
                                
                                    
                                        作者:Kavirayani R. Prasad、Shivajirao L. Gholap                                    
                                    
                                        DOI:10.1021/jo0702342
                                    
                                    
                                        日期:2008.1.1
                                    
                                    [GRAPHICS]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.