Regio- and stereo-controlled synthesis of bicyclic α-methylene-γ-butyrolactones containing a fluorine via halofluorination-radical cyclization
作者:Makoto Shimizu、Osamu Morita、Satoru Itoh、Tamotsu Fujisawa
DOI:10.1016/s0040-4039(00)60917-6
日期:1992.11
regio- and stereoselective halofluorination with pyridinium poly(hydrogen fluoride) and 1,3-dibromo-5,5-dimethylhydantoion or N-iodosuccinimide to give (1S*,2S*,3S*)-1-alkoxy-3-fluoro-2-halocycloalkanes in good yields. Among the halofluorides, the 3-(2-propynyloxy) derivatives are in turn converted into bicyclic α-methylene-γ-butyrolactons containing a fluorine via radical cyclization followed by oxidation
3-烷氧基环烯烃与吡啶鎓聚(氟化氢)和1,3-二溴-5,5-二甲基乙内酰脲或N-碘代琥珀酰亚胺进行区域和立体选择性卤代氟化反应,得到(1 S *,2 S *,3 S *)-1-烷氧基-3-氟-2-卤代环烷烃收率高。在卤代氟化物中,3-(2-丙炔氧基)衍生物通过自由基环化反应继而被氧化成含氟的双环α-亚甲基-γ-丁内酯,然后氧化,导致立体立体合成(±)-4-氟- l- Epi- damsin。