Organoselenium mediated asymmetric cyclizations. Synthesis of enantiomerically pure 1,6-dioxaspiro[4.4]nonanes
作者:Marcello Tiecco、Lorenzo Testaferri、Luana Bagnoli、Catalina Scarponi、Andrea Temperini、Francesca Marini、Claudio Santi
DOI:10.1016/j.tetasy.2006.10.021
日期:2006.10
mixture of two diastereoisomeric E- and two diastereoisomeric Z-2-[(camphorseleno)methyl]-1,6-dioxaspiro[4.4]nonanes. These were separated by medium pressure liquid chromatography and then deselenenylated with triphenyltin hydride and AIBN to give enantiomerically pure 2-methyl-1,6-dioxaspiro[4.4]nonanes. The camphorseleno group was also substituted by an allyl function using allyltributyltin in the presence
在室温下,由樟脑二硒化物和四氟硼酸银在二氯甲烷中生成的樟脑硒烯基四氟硼酸酯促进了1-羟基辛-7-en-4-one的不对称环化反应,得到了两种非对映异构体E-和两种非对映异构体Z -2- [ (樟脑硒基)甲基] -1,6-二氧杂螺[4.4]壬烷。将它们通过中压液相色谱分离,然后用氢化三苯锡和AIBN去硒烯基化,得到对映体纯的2-甲基-1,6-二氧杂螺[4.4]壬烷。在AIBN存在下,使用烯丙基三丁基锡也将烯丙基官能团取代了樟脑硒基。