Method of synthesizing optically enriched alpha-halo-esters, and product and composition therefrom
申请人:——
公开号:US20030050501A1
公开(公告)日:2003-03-13
A method of synthesizing highly optically enriched &agr;-halo-esters comprises reacting acid halides with a cinchona alkaloid catalyst and a base to form intermediate ketenes. The ketenes are reacted with electrophilic halogenating reagents to produce &agr;-halo-esters with high enantiomeric excess. The base can be an inorganic salt. The thus-formed &agr;-halo-esters have utility in synthesizing other optically-pure materials.
The Development of the First Catalyzed Reaction of Ketenes and Imines: Catalytic, Asymmetric Synthesis of β-Lactams
作者:Andrew E. Taggi、Ahmed M. Hafez、Harald Wack、Brandon Young、Dana Ferraris、Thomas Lectka
DOI:10.1021/ja0258226
日期:2002.6.1
resulting from the development of a catalyzed reaction of ketenes (or their derived zwitterionic enolates) and imines. The products of these asymmetric reactions can serve as precursors to a number of enzyme inhibitors and drug candidates as well as valuable synthetic intermediates. We present a detailed study of the mechanism of the beta-lactam forming reaction with proton sponge as the stoichiometric
discover biorational natural products-based insecticides, two series (27) of novel 9R/S-acyloxy derivatives of cinchonidine and cinchonine were prepared and assessed for their insecticidal activity against Mythimna separata in vivo by the leaf-dipping method at 1 mg/mL. Among all the compounds, especially derivatives 6l and 6o exhibited the best insecticidal activity with final mortality rates of 75
Preparation of Enantiopure 1-Azabicyclo[3.2.2]nonanes Functionalized at Carbon C3, from Cinchonine and Cinchonidine. Stereoselective Solvolysis and an Easily Enolizable Ketone
作者:Stefanie Röper、M. Heiko Franz、Rudolf Wartchow、H. Martin R. Hoffmann
DOI:10.1021/jo026890d
日期:2003.6.1
Solvolysis of C9 mesylated cinchonidine 1-OMs and cinchonine 2-OMs in solvent MeOH, EtOH, and CF3CH2OH affords ring-expanded 1-azabicyclo[3.2.2]nonanes oxygenated at carbon C3 ("second Cinchona rearrangement"). The newly introduced substituents at C3 and the neighboring quinolyl group Q' at C2 adopt quasiequatorial positions. The derived 1-azabicyclo[3.2.2]nonan-3-ones 5 and 6 are easily equilibrated. On contact with MeOD uptake of deuterium takes place at room temperature.
Hilditch, Journal of the Chemical Society, 1911, vol. 99, p. 228