Synthesis 2006(7): 1111-1116  
DOI: 10.1055/s-2006-926383
PAPER
© Georg Thieme Verlag Stuttgart · New York

Synthesis of γ-(2,4-Dioxobut-1-ylidene)butenolides by Reaction of Masked 1,3-Dicarbonyl Dianions with Maleic Anhydrides and Phthaloyl Dichloride

Uwe Albrechta, Van Thi Hong Nguyena, Peter Langer*b,c
a Institut für Chemie und Biochemie, Universität Greifswald, Soldmannstr. 16, 17487 Greifswald, Germany
b Institut für Chemie, Universität Rostock, Albert-Einstein-Str. 3a, 18059 Rostock, Germany
c Leibniz-Institut für Katalyse e. V. an der Universität Rostock, Albert-Einstein-Str. 29a, 18059 Rostock, Germany
Fax: +49(381)4986412; e-Mail: peter.langer@uni-rostock.de;
Further Information

Publication History

Received 5 September 2005
Publication Date:
08 March 2006 (online)

Abstract

γ-(2,4-Dioxobut-1-ylidene)butenolides were prepared with very good regioselectivity by reaction of (2,4-dioxobutylidene)triphenylphosphoranes with maleic anhydrides. The reaction of 1,3-bis-silyl enol ethers with phthaloyl dichloride afforded benzo-annulated γ-(2,4-dioxobut-1-ylidene)butenolides; the formation of these products can be explained by formation of iso-phthaloyl dichloride and attack of the bis-silyl enol ether onto the latter.