• Title/Summary/Keyword: Thiiranes

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The Synthesis of 2-Methyl-5,5'-gem-Disubstituted-${\Delta}^2$-Thiazolines (2-Methyl-5,5'-gem-Disubstituted-${\Delta}^2$-Thiazoline系 化合物의 合成)

  • Chi Sun Hahn
    • Journal of the Korean Chemical Society
    • /
    • v.7 no.4
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    • pp.230-237
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    • 1963

  • The synthesis of 2-methyl-5,5'-gem-disubstituted-$\Delta^2$-thiazolines has been undertaken by two methods. The first involves the preparation of gem-disubstituted N-or S-acetylamino mercaptan intermediates by ring opening of the corresponding thiiranes with ammonia. The second consists of the ring opening of gem-disubstituted ethylene imines using thiolacetic acid. The thiirane rings have never been opened under conditions as vigorous as that of using sodium amide in liquid ammonia. This is probably due to retardation by the gem-disubstituents. In contrast to this, the corresponding ethylene imine ring opens easily, in spite of the same stereochemical situation. The stabilization of gem-disubstituted cyclic compounds has been discussed from a stereochemical point of view. It has been concluded from the results of this work that the compression effect of gem-disubstitution is not due to bond angle deformation, which was observed by Thorpe and Ingold, but mostly to an electronic bond interaction of the gem-disubstituents and to the hetero atom(s), if any.

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