HELVETICA CHIMICA ACTA, cilt.95, sa.8, ss.1409-1424, 2012 (SCI-Expanded)
The [Cu(acac)2]-catalyzed reactions of various alpha,beta,gamma,delta-unsaturated bis-ketones/bis-esters/bis-keto esters with dimethyl diazomalonate and ethyl diazoacetate were studied. Total steric/electronic convenience of the present reaction paths was investigated. Methoxy/nitro substituents in m-/p-positions on benzylidene biscarbonyls did not alter the general routes of the reactions, supporting concerted mechanism. Dihydrobenzoxepine/oxepine formation was sterically sensitive to the related pre-ring conformation, and dihydrofurans were effected by both charge control and steric factors.