A new furan annelation by the palladium-catalyzed reaction of 2-alkynyl carbonates with β-keto esters is described. The reaction proceeds under mild neutral conditions and hence unstable 3-alkylidene-2,3-dihydrofurans can be prepared in this way. Similarly, reaction of 2-(1-alkynyl)oxiranes with β-keto esters gives alkylidene furans.
Preparation of unstable 3-alkylidene furans by the palladium-catalyzed reaction of α-alkynyl epoxides with β-keto esters
作者:Ichiro Minami、Masami Yuhara、Jiro Tsuji
DOI:10.1016/s0040-4039(00)95798-8
日期:——
Palladium-catalyzed reaction of α-alkynyl epoxides with β-keto esters gives unstable 3-alkylidene-2,3-dihydrofuran-4-carboxylates. It can be carried out under mild neutral conditions, and offers a good preparative method for 3-alkylidene furans.