title: Base-catalyzed highly stereoselective conversion of gamma-hydroxy-alpha,beta-acetylenic esters to gamma-acetoxy dienoates.
abstract: Gamma-hydroxy-alpha,beta-acetylenic esters can be conveniently prepared from the reaction of methyl propiolate with aldehydes in the presence of ZnEt(2) and N-methylimidazole at room temperature. It is discovered that the gamma-hydroxy-alpha,beta-acetylenic esters can be catalyzed by p-N,N-dimethylaminopyridine (DMAP) in acetic anhydride to generate the gamma-acetoxy dienoates with high stereo control. The mechanism of this conversion is investigated by NMR analyses and isotope labeling experiments. An intramolecular Diels-Alder reaction of a gamma-acetoxy dienoate is conducted to show the synthetic potential of these compounds.
authors.affiliation: Department of Chemistry, University of Virginia, Charlottesville, Virginia 22904, USA.
authors.forename: Yang
authors.initials: Y
authors.lastname: Yue
authors.forename: Xiao-Qi
authors.initials: XQ
authors.lastname: Yu
authors.forename: Lin
authors.initials: L
authors.lastname: Pu