Graduate School of Chemical Sciences and Engineering, Hokkaido University, Sapporo 060-0810, Japan.
Department of Chemistry, Faculty of Science, Hokkaido University, Sapporo 060-0810, Japan.
Org Lett. 2021 Nov 19;23(22):8878-8882. doi: 10.1021/acs.orglett.1c03383. Epub 2021 Oct 29.
A method for the synthesis of 3-methylene-1,4-cycloheptadiene derivatives via an 8π electrocyclization reaction was developed. The triene substrate bearing a phosphate or carbamate group was prepared from γ,δ-unsaturated esters and α,β-unsaturated aldehydes in four steps. Upon treatment with NaHMDS or KHMDS, the substrate formed a heptatrienyl anion, which underwent electrocyclization and subsequent β-elimination of the leaving group. The product could be converted into a tropylium salt in two steps.
通过 8π 电环化反应，开发了一种合成 3-亚甲基-1,4-环庚二烯衍生物的方法。该三烯底物是通过γ,δ-不饱和酯和α,β-不饱和醛在四步反应中制备的，带有磷酸酯或氨基甲酸酯基团。用 NaHMDS 或 KHMDS 处理后，底物形成了庚三烯阴离子，它经历电环化和随后离去基团的β消除。产物可以通过两步转化为卓鎓盐。
