The vitamin D A-ring synthon, the enyne 3b, was synthesized in 5 steps (37% overall yield) from (S)-(+)-carvone (5). The key step was the SmI2-Pd0 mediated transformation of epoxypropargyl ester 6 to 3b.
由(S)-(+)-
香芹酮(5)分5步(总收率37%)合成了
维生素D A环合成子烯炔3b。关键步骤是SmI 2 -Pd 0介导的环氧炔丙基酯6到3b的转化。