Enantiodivergent synthesis of cytotoxic styryl lactones from d-xylose. The first total synthesis of (+)- and (−)-crassalactone C
作者:Velimir Popsavin、Goran Benedeković、Bojana Srećo、Jovana Francuz、Mirjana Popsavin、Vesna Kojić、Gordana Bogdanović、Vladimir Divjaković
DOI:10.1016/j.tet.2009.10.079
日期:2009.12
Enantiodivergent total syntheses of both (+)- and (−)-enantiomers of goniofufurone, 7-epi-goniofufurone and crassalactone C have been accomplished starting from d-xylose. The key steps of the synthesis of 7-epi-(+)-goniofufurone were a stereo-selective addition of phenyl magnesium bromide to a protected dialdose, and a stereospecific furano–lactone ring formation by reaction of a related hemiacetal
从d-木糖开始已经完成了对角呋喃酮,(7-表-对角呋喃酮和克拉沙内酯C )的(+)-和(-)-对映体的对映体总合成。合成7- Epi的关键步骤-(+)-goniofufurone是将苯基溴化镁立体选择性加成到受保护的二糖中,以及相关半缩醛衍生物与Meldrum酸反应形成的立体特异性呋喃-内酯环。(+)-gonfufufurone和(+)-crassalactone C的合成都需要在普通中间体中的C-5处进行构型转化,这可以在标准的Mitsunobu条件下有效地实现,或者通过依次氧化苄基羟基随后进行硼氢化物的立体选择性还原。然后将类似的方法应用于gonfufufurone,7- epi的非天然(-)-对映异构体的合成-goniofufurone和crassalactone C,以及(+)-和(-)-goniofufurone的两个新颖的,受构象约束的类似物。记录了它们对多种人类肿瘤细胞系的体