Solvent-free synthesis of 4,4-bis-functionalized-1,6-dienes and 1,6-diynes on the surface of neutral alumina

An improved procedure has been developed for the synthesis of structurally varied 4,4-bis-functionalized-1,6-dienes and 1,6-diynes through regioselective alkylation of active methylene compounds with several unsymmetrical allyl bromides and propargyl bromide on the surface of neutral alumina impregnated with sodium ethoxide or potassium tert-butoxide in the absence of any solvent under environmentally benign conditions. (C) 2001 Elsevier Science Ltd. All rights reserved.