- 作者: 周善行 ; 孫德崢 ; 戴海萍
- 作者服務機構: 輔仁大學化學系
- 中文摘要: Bromination of 3-phenylthio-2-sulfolene with N- bromosuccinimide gave 2-bromo-3-phenylthio-2-sulfolene which was converted mainly to 2,3-bis(phenylthio)-2- sulfolene (4) by treatment with sodium phenylthiolate. Thermal desulfonylation of 4 at different temperatures in the presence of a base (DBU) yielded stereoselectively the(Z)- and (E)-1,2-bis(phenylthio)-1,3-butadiene (6). These two geometric isomers could be thermally interconverted. The Diels-Alder reactions of 6 were also investigated. Only the(Z)-diene (6a) could undergo the Diels-Alder reaction; the(E)-diene was in situ converted to the Z isomer before undergoing the Diels-Alder reaction. The reaction off 6a with N-phenylmaleimide gave the cycloaddition product 7 with complete endo selectivity, but under daylight or during chromatography it readily underwent a thioallylic rearrangement to yield 8 with inversion of configuration. The cycloaddition of 6a with methyl acrylate proceeded regiospecifically, but generating a mixture of endo and exo isomers. The endo/exo ratio could be increased by using ZnCl/sub 2/ as the catalyst.
- 英文摘要: --
- 中文關鍵字: Stereoselective Synthesis; Diels-Alder Reaction; Thermal Desulfonylation; Rearrangement; Cycloaddition
- 英文關鍵字: 立體選擇反應;Diels-Alder反應;熱脫硫醯;重排;環加成