A Remarkably Stable and Simple Monocyclic Thiepin . Synthesis and Properties of 2 , 7 - Di - tert - butyl - 4 - ethoxycarbonyl - 5 - methylthiepin
نویسنده
چکیده
A simple monocyclic 8n electron thiepin, 2,7-di-tert-butyl-4-ethoxycarbonyl-5-methylthiepin (13) stabilized by two bulky tert-butyl groups at 2and 7-positions, was synthesized from 2,6-di-tert-butyl-4-methylthiopyrylium tetrafluoroborate (11). In spite of of its monocyclic thiepin structure, the compound 13 showed remarkable thermal stability and had a half-life of 7.1 h at 130 °C. Judging from the 1H-NMR spectrum, the thiepin 13 is considered to be an atropic molecule. Synthetic details of 11 and 13, and the chemical and physical properties of 13 are also described.
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