Enantio- and Diastereoselective Synthesis of β,γ,γ,δ-Tetrasubstituted α-Methylene-δ-lactones
作者:Henryk Krawczyk、Łukasz Albrecht、Dariusz Deredas、Jakub Wojciechowski、Wojciech Wolf
DOI:10.1055/s-0031-1289629
日期:2012.1
The synthesis of two α-(diethoxyphosphoryl)-α,β-unsaturated δ-lactones with 98% ee has been developed using (S)-3-aryl-3-hydroxy-2,2-dimethylpropanals, easily accessible via direct, asymmetric organocatalytic aldol reaction, as the starting materials. The lactones were transformed into the corresponding α-methylene-δ-lactones in a two-step process involving Michael addition followed by Horner-Wadsworth-Emmons
使用(S)-3-芳基-3-羟基-3-羟基-2,2-二甲基丙醛开发了两种α-(二乙氧基磷酰基)-α,β-不饱和δ-内酯的合成方法,可以容易地通过直接,不对称获得有机催化的羟醛反应,作为起始原料。内酯通过两步法转化为相应的α-亚甲基-δ-内酯,包括迈克尔加成反应,然后进行霍纳-沃兹沃思-埃蒙斯烯化反应,而不损失对映体纯度。此外,显示了迈克尔加成的非对映选择性可以由中间体内酯中的C6立体异构中心完全控制。提出了合理化反应立体化学结果的过渡态模型。 Knoevenagel缩合-Michael加成-HWE烯化-β-羟醛-α-亚甲基-δ-内酯