stereoselective synthesis of the cytotoxic 14-membered macrolide aspergillide A has been performed. The preparation of a cis-2,6-disubstituted tetrahydropyran ring via stereoselective reduction of an intermediate cyclic hemiacetal was one key feature of the synthesis. The macrocyclic lactone ring was created by means of a ring-closing metathesis (RCM), whereby the new C═C bond displayed exclusively
已经进行了细胞毒性的14元大环内酯曲霉内酯A的立体选择性合成。通过立体选择性还原中间环状
半缩醛制备顺式-2,6-二取代的
四氢吡喃环是合成的关键特征之一。大环内酯环是通过闭环复分解(RCM)产生的,由此新的C═C键仅显示出不希望的Z构型。通过光
化学异构化转化为所需的E构型。