Synthesis of Heterocycles via Alkoxyallenes.
T. Lechel, H.-U. Reissig – 2010
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.