1,3-Dipolar Cycloadditions, 97. – Some Cycloadditions of Aromatic ThioneS-Oxides
作者:Rolf Huisgen、Grzegorz Mloston、Kurt Polborn、Francisco Palacios-Gambra
DOI:10.1002/jlac.199719970127
日期:1997.1
Surprisingly, thiobenzophenone S-oxide (5) and thione 6 afforded the spiro-1,2,4-trithiolane 7 (86%) instead of the expected spiro-1,2,4-oxadithiolane 16. Structure 7 was established via spectra, single-crystal X-ray analysis, and an independent synthesis from thiobenzophenone S-sulfide (15) and 6. On accepting the formation of 16 by 1,3-cycloaddition as a first step, we reduced the mechanistic problem
出人意料的是,硫代二苯甲酮S-氧化物(5)和硫酮6提供了螺1,2,4-三硫杂环戊烷7(86%),而不是预期的螺1,2,4-氧杂二硫杂环戊烷16。结构7是通过光谱,单晶X射线分析以及硫代二苯甲酮S-硫化物(15)和6的独立合成建立的。在第一步中接受通过1,3-环加成反应形成16的过程中,我们将机理问题简化为转化16 + 6 15 +二酮8;讨论了三种可能的途径。硫芴酮S氧化物(25)与6结合成三硫杂环戊烷27,产率低;25到9,9'-联芴基(26)的自发转化优先。5与(E)-环辛烯(28)的1:1反应中不涉及1,3-环加成。图5作为杂1,3-二烯与28结合成Diels-Alder型加合物30。