Polar vs steric effects in the 1,3-dipolar cycloaddition reactions of acetonitrile oxide and 2-endO-acetoxy-5-halo-7-oxabicyclo[2.2.1]hept-5-en-2-exo-carbonitrile
作者:Odön Arjona、Alfonso de Dios、Roberto Fernandez de la Pradilla、Araceli Mallo、Joaquin Plumet
DOI:10.1016/s0040-4020(01)81474-5
日期:——
The regioselectivity of the cycloaddition reactions between acetonitrile oxide and a number of 7-oxabicyclo[ 2.2.1]hept-5-enes is discussed. Acetonitrile oxide adds with complete regioselectivity to 2-endo-acetoxy-5-halo-7-oxabicyclo[2.2.1]hept-5-en-2-exo-carbonitriles. Kinetic measurements indicate a more polar transition state for 2a than for the unsubstituted substrate la
Racemic 6-ethenyl-7-oxabicyclo[2.2.1]hept-5-en-2-one (23), 5-ethenyl-7-oxabicyclo[2.2.1]hept-5-en-2-one (25) and their ethylene acetals 24 and 26, respectively, were derived from the Diels-Alder adduct of furan to 1-cyanovinyl acetate (27). The Diels-Alder additions of 26 to dimethyl acetylenedicarboxylate, to methyl propynoate, to N-phenylmaleimide, and to methyl acrylate were highly exo-face selective
Control of the Regioselectivity in the Pauson−Khand Reaction of 7-Oxanorbornene Derivatives
作者:Odón Arjona、Aurelio G. Csákÿ、M. Carmen Murcia、Joaquín Plumet
DOI:10.1021/jo9903095
日期:1999.10.1
The regiochemistry of the Pauson-Khand reaction of 7-oxanorbornene derivatives can be influenced by a remote substituent at carbon C-2. Furthermore, a remarkable effect on the regiochemical outcome of this reaction was observed by halide substituents in the olefin carbons, which may be utilized as an element of control of regioselectivity.
Total asymmetric syntheses of d-lividosamine and 2-acetamido-2,3-dideoxy-d-arabino-hexose derivatives.
作者:Etienne de Buchteneere、Daniela Fattori、Pierre Vogel
DOI:10.1016/s0040-4020(01)88357-5
日期:1992.11
Meerpoel Lieven, Vrahami Maria-Miranda, Deguin Brigitte, Vogel Pierre, Helv. chim. acta, 77 (1994) N 3, S 869-881
作者:Meerpoel Lieven, Vrahami Maria-Miranda, Deguin Brigitte, Vogel Pierre