Stereoselective synthesis of polyether antibiotics, lasalocid A and isolasalocid A, via a chelation-controlled formation of tetrahydrofuran rings under thermodynamic conditions
作者:Ichio Noda、Kiyoshi Horita、Yuji Oikawa、Osamu Yonemitsu
DOI:10.1016/s0040-4039(00)98022-5
日期:1990.1
of lasalocid A (6) and isolasalocid A (7) were stereoselectively constructed from the corresponding p-methoxyphenylallyl alcohols (13a, 13b) by treatment with ZnBr2 to give C13-C24 fragments (14a, 14b) via a new chelation-controlled cyclization under thermodynamic conditions. After their conversion into lasalocid ketone (19) and BOM-isolasalocid ketone (20), coupling with the C1-C11 aldehyde (22) completed
所述B环(2,5-反式拉沙里菌素A(的-tetrahydrofurans)6)和isolasalocid A(7)的立体选择性地从相应的构造p -methoxyphenylallyl醇(13A,13B)通过用ZnBr 2得到C,13 -在热力学条件下通过新的螯合控制环化作用使C 24片段(14a,14b)断裂。将其转化为拉索洛酮(19)和BOM-异拉索酮(20)后,与C 1 -C 11醛(22)分别完成了6和7的合成。