Synthesis of heterocycles via alkoxyallenes

Lechel, Tilman; Reissig, Hans-Ulrich

doi:10.1351/PAC-CON-09-09-06

Pure Appl. Chem., 2010, Vol. 82, No. 9, pp. 1835-1844

http://dx.doi.org/10.1351/PAC-CON-09-09-06

Published online 2010-05-30

Synthesis of heterocycles via alkoxyallenes

Tilman Lechel and Hans-Ulrich Reissig*

Institute of Chemistry and Biochemistry, Freie Universität Berlin, Takustrasse 3, D‑14195 Berlin, Germany

Abstract: Lithiated alkoxyallenes are very versatile components for the synthesis of heterocycles such as furans, pyrroles, and 1,2-oxazines, easily allowing the preparation of natural products via these heterocyclic intermediates. A surprising three-component synthesis of N‑acylated enaminones allowed the synthesis of highly functionalized 4-hydroxypyridines, 5‑acetyloxazoles, and pyrimidines. All these heterocyclic products are ready for further functionalizations, in particular for palladium-catalyzed reactions, leading to libraries of new interesting heterocycles.