A Simple and Efficient Synthesis of Heterocycle-Fused 2H-Thiopyrans, Furo-, Benzofuro-, Thieno-, Benzothieno-, Pyrrolo- and Indolo-2H- thiopyrans, from Heteroaromatic Thioketones and α-Chloroacrylonitrile or α-Bromoacrylic Esters via a Hetero Diels-Alder Reaction-Dehydrohalogenation Process
THE REACTION OF 2<i>H</i>-THIIN DERIVATIVES WITH PERACID. RING CONTRACTION AND ALKOXYLATION REACTIONS
作者:Haruo Ohmura、Shinichi Motoki
DOI:10.1246/cl.1984.1973
日期:1984.11.5
The cycloaddition reaction of aromatic thioketones (aryl naphthyl thioketones and 2-benzofuryl phenyl thioketone) with 2-chloroacrylonitrile followed by elimination of hydrogen chloride gave some 2H-thiin derivatives. The products reacted with MCPBA and an alcohol to afford ring-contracted product and alkoxylated derivatives.
OHMURA, HARUO;MOTOKI, SHINICHI, CHEM. LETT., 1984, N 11, 1973-1976
作者:OHMURA, HARUO、MOTOKI, SHINICHI
DOI:——
日期:——
A Simple and Efficient Synthesis of Heterocycle-Fused 2<i>H</i>-Thiopyrans, Furo-, Benzofuro-, Thieno-, Benzothieno-, Pyrrolo- and Indolo-2<i>H</i>- thiopyrans, from Heteroaromatic Thioketones and α-Chloroacrylonitrile or α-Bromoacrylic Esters via a Hetero Diels-Alder Reaction-Dehydrohalogenation Process
An efficient and convenient procedure is described for the synthesis of heterocycle-fused 2H-thiopyrans having ortho-dimethylene structures via a hetero Diels-Alder reaction-dehydrohalogenation process starting from heteroaromatic thioketones and α-chloro-acrylonitrile or α-bromoacrylates.
The reaction of 3-cyano-2H-thiin derivatives with chloramine salt or diazomalonate gave the corresponding sulfilimines or sulfonium ylides and dihydrothiepin derivatives. These products rearranged by the action of DBU eventually to afford pyridine derivatives or benzofuran and benzothiophene derivatives.