[4 + 2]-Annulations of Chiral Organosilanes: Application to the Total Synthesis of Leucascandrolide A
作者:Qibin Su、Les A. Dakin、James S. Panek
DOI:10.1021/jo0610412
日期:2007.1.1
Complete details of an asymmetric synthesis of leucascandrolide A (1) are described. The synthesis highlights the use of two diastereoselective [4 + 2]-annulations for the assembly of the functionalized bispyranyl macrolide 3. An efficient assembly and union of the oxazole-containing side chain 4 with macrolide 3 was carried out using a Mitsunobu reaction. A convergent route to the oxazole side chain
描述了leucascandrolide A(1)的不对称合成的完整细节。该合成突出显示了两个非对映选择性[4 + 2]环的功能化双吡喃基大环内酯3的组装。使用Mitsunobu反应进行了含恶唑侧链4与大环内酯3的有效组装和结合。利用2-三氟噻唑16和炔烃17之间的Sonogashira交叉偶联,开发了向恶唑侧链的收敛路线,从而可以安装C9'-C10'(Z)-烯烃。