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.
Ma
Shengming
S
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
Wu
Bin
B
Zhao
Shimin
S