For the purpose of synthesizing daphnezomine C, model systems were examined to see if the ring-closing metathesis (RCM) reaction could be applied to prepare an 11-membered ring system bearing a tri-substituted alkene. As a result, it was found that the connectivity pattern of the tethers bearing the reacting alkene moieties was crucial. Thus, whereas a system involving a single 1,3- or 1,4-disubstituted cyclohexane derivative did not give RCM products, a flexible system without any rings between the two terminal alkenes gave the cyclic product with a yield of up to 65% using the second generation Grubbs catalyst.
为了合成达夫尼佐明 C,研究人员对模型体系进行了研究,以确定能否应用闭环偏合成(RCM)反应来制备含有三取代烯的 11 元环体系。结果发现,带有反应烯分子的三元环的连接模式至关重要。因此,虽然涉及单一 1,3- 或 1,4- 二取代
环己烷衍
生物的体系不会产生 RCM 产物,但使用第二代 Grubbs 催化剂,在两个末端烯之间没有任何环的柔性体系可以产生环状产物,产率高达 65%。