作者:Claire Gregg、Michael V. Perkins
DOI:10.1016/j.tet.2012.10.008
日期:2013.1
the key C22–23 aldol coupling for the synthesis of spirangiens A & B. The lithium enolate of model ketone 3 was coupled with the differently protected aldehydes 4 (acetonide) and 5 (silyl) giving 3:1 and 3.5:1 dr, respectively, in favour of the unnatural (S) isomer in both cases. The lack of any significant effect on the aldol stereoselectivity induced by the aldehyde protecting groups contrasts with
制备了一个模型系统,以研究关键的C22-23醛醇偶合体对合成螺旋藻A和B的非对映选择性。模型3的烯醇锂与不同保护的醛4(丙酮化物)和5(甲硅烷基)结合,在两种情况下,分别使用3:1和3.5:1 dr都支持非天然(S)异构体。由醛保护基诱导的对醛醇的立体选择性没有任何显着影响,这与以前的文献报道形成了对比。