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[摘要]：Delta(4)-Primary alkenols (Z)- and (E)-hex-4-en-1-ols underwent facile cyclization to the corresponding phenyl selenoethers using PhSeX (X = Cl, Br) in high yields and in good to excellent selectivities in the presence of some catalysts (Lewis acids and bases). The reaction succeeded in complete control of stereo- and regioselectivity. The best results were obtained with triethylamine and tin(II) chloride. Triethylamine as an additive in the reaction with (Z)-hex-4-en-1-ol gives only erythro-2-[1-(phenylseleno)ethyl]tetrahydrofuran, while the E-isomer gives cis-2-methyl-3-(phenylseleno)tetrahydropyran in large excess. Tin(II) chloride as an additive in the reaction with (Z)-hex-4-en-1-ol gives threo-2-[1-(phenylseleno)ethyl]tetrahydrofuran and with the E-isomer gives trans-2-methyl-3-(phenylseleno)tetrahydropyran. The reactions were performed under very mild experimental conditions, and the obtained yields were almost quantitative. |
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