作者:Erhan Er、Paul Margaretha
DOI:10.1002/hlca.19920750712
日期:1992.11.11
Reaction of 3-bromo-3-methylbutan-2-one (1) with mercapto-esters 2 affords 5-oxo-3-thiahexanoates 3 which cyclize to thiane-3,5-diones 4. Conversion of these dicarbonyl compounds to their ethyl enol ethers 5–7 followed by reduction with LiAlH4 gives 2H,6H-thiin-3-ones 8–10. On irradiation (350 nm) in either MeCN, benzene, or i-PrOH, these newly synthesized heterocycles isomerize efficiently to 2-(
3-溴-3-甲基丁-2-(1)与巯基酯2的反应得到5-氧代-3-硫代己酸酯3,其环化成噻吩-3,5-二酮4。将这些二羰基化合物转化为它们的乙烯醇醚5-7,然后用LiAlH 4还原,得到2 H,6 H -thinth-3-ones 8-10。在MeCN,苯或i-PrOH中进行辐照(350 nm)时,这些新合成的杂环有效地异构化为2-(alk-1-烯基)thietan-3-ones 11-13。重排似乎是从激发的单重态开始的,因为它没有被萘淬灭,并且在添加烯烃的情况下也以相同的效率发生。作为可能的中间体,讨论了通过将烯酮CC键的C(α)键合到硫上而形成的(9-S-3)硫烷基-双自由基。