Abstract: 2-(Alkylidene)tetrahydrofurans are prepared by cyclization of 1,3-dicarbonyl dianions or 1,3-bis(silyloxy)-1,3-butadienes with various electrophiles. The products represent versatile building blocks for hydrogenation, cross-coupling, bromination and oxidation reactions.

Reviews: Tetrahedron 2007, 63, 10865-10888; Chem. Rev. 2004, 104, 4125-4149.

Period of investigation: 1999 – 2007

Keywords: 1,3-dicarbonyl compounds; dianions; silyl enol ether; cyclizations; heterocycles