Synfacts 2007(1): 0030-0030  
DOI: 10.1055/s-2006-955740
Synthesis of Heterocycles
© Georg Thieme Verlag Stuttgart · New York

2-Alkenylfurans via Feist-Benary and Wittig Reactions

Contributor(s): Victor Snieckus, Bärbel Wittel
G. Mross, E. Holtz, P. Langer*
Universität Rostock, Georg-August-Universität Göttingen and Leibniz-Institut für Katalyse e.V. an der Universität Rostock, Germany
Further Information

Publication History

Publication Date:
15 December 2006 (online)

Significance

3-Acyl-2-alkenylfurans are prepared by the Feist-Benary cyclocondensation of (2,4-dioxo-butylidene)phosphoranes with α-halo­ketones or α-chloroacetaldehyde followed by an E-diastereoselective Wittig reaction. The starting (2,4-dioxobutylidene)phosphorane is readily available from the reaction of Ph3P with ethyl 4-chloro­acetoacetate. The scope of the reaction was tested for a variety of different R1 and R2 substituents but little variation in R3. The olefin contained alkyl, alkenyl, EWG as well as EDG substituents. The high E-diastereoselectivity of the Wittig reaction is probably due to the presence of Li salt in the reaction mixture. Generally, the diastereoselectivity of the products was found to be much higher when aromatic aldehydes rather than aliphatic aldehydes were employed.