Sixteen-membered macrolide aglycons with different oxidation levels, leuconolide A1 (3a), leuconolide A3 (3b), midecanolide A1 (3c), maridonolide II (4a), and maridonolide I (4b), were synthesized from two carbonolide type compounds (1, 2) by stereoselective reduction and epoxidation on the 16-membered ring system. The conformational analysis of macrolide rings based on nuclear magnetic resonance measurements and MMP2 calculations is also discussed in relation to the stereoselective synthesis of the five macrolide aglycons (3a-4b).
十六元环大环内酯无糖苷具有不同的氧化
水平,分别是
白藜芦醇A1(3a)、
白藜芦醇A3(3b)、米德卡诺内酯A1(3c)、马里多诺内酯II(4a)和马里多诺内酯I(4b),它们是由两种羰基化合物(1、2)通过在16元环系统上进行立体选择性还原和环氧化反应合成的。此外,还讨论了基于核磁共振测量和MMP2计算的大环内酯环构象分析,以及五种大环内酯无糖苷(3a-4b)的立体选择性合成。