HELVETICA CHIMICA ACTA, cilt.86, sa.2, ss.290-298, 2003 (SCI-Expanded)
Carbonyl ylides arising from ethyl acetodiazoacetate/dimethyl diazomalonate and a,beta-enones with mainly s-cis conformations underwent disrotatory cyclization to produce dihydrofuran derivatives. This process proved to be sensitive to steric effects. The corresponding ylides arising from rather s-trans a,beta-enals yielded dioxole derivatives. The mechanisms of the reactions are discussed.