Mild and efficient synthesis of (Z)-alpha-chloroalkylidene-beta-lactones via the PdCl2-catalyzed cyclocarbonylation of 2-alkynols.
[reaction: see text] A mild and efficient methodology involving PdCl(2)-catalyzed cyclocarbonylation of 2-alkynols with CuCl(2) for the synthesis of (Z)-alpha-chloroalkylidene-beta-lactones was developed. Using the readily available optically active propargylic alcohols allows convenient synthesis of the corresponding (Z)-alpha-chloroalkylidene-beta-lactones with high ee values. cis-Chloropalladation was observed as the major pathway, which is unique as compared to the reported data.
State Key Laboratory of Organometallic Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, 354 Fenglin Lu, Shanghai 200032, P. R. China. masm@mail.sioc.ac.cn
Shengming
S
Ma
Bin
B
Wu
Shimin
S
Zhao