vitamin B12, and their 20-cyano analogues, have been synthesised by a mild route compatible with the side-chains of natural isobacteriochlorins; this involves assembly of the A–D ring system using a Witting-type reaction and finally photochemical ring-closure to the macrocycle.
与
维生素B 12及其20-
氰基类似物的
生物合成研究有关的重要20-甲基异
氯霉素已通过与天然异
氯霉素侧链相容的温和途径合成。这包括使用Witting型反应组装A-D环系统,最后将光
化学环封闭到大环上。