The Reaction of Cyclic 1,3-Diketones with Alkylthiocydopropenium Ions to Yield 2-Alkylthio-substituted 2<i>H</i>-Pyrans
作者:Hiroshi Yoshida、Mikito Nakajima、Tsuyoshi Ogata、Kiyoshi Matsumoto
DOI:10.1246/bcsj.57.734
日期:1984.3
This study treats the reactions of methylthio-, ethylthio-, or benzylthiodiphenylcyclopropenium ion (1) with 5-, 6-, and 7-membered cyclic 1,3-diketones, giving either 2-alkylthio-2H-pyrans or dienone derivarives. Treatment of 1 with 1,3-cyclopentanedione, 1,3-cyclohexanedione, 5,5-dimethyl-1,3-cyclohexanedione, 4-hydroxy-6-methyl-2-pyrone, 4-hydroxycoumarin, and 1,3-cycloheptanedione in the presence of triethylamine afforded 2-alkylthio-2H-pyrans. The structure of the products was elucidated on the basis of their elemental analyses, IR, 1H-NMR, 13C-NMR, and mass spectroscopic data, as well as chemical transformations. 2-Alkylthio-2H-pyrans with mercury(II) chloride in an alcohol underwent conversion to the corresponding 2-alkoxy-2H-pyrans. The 1H- and 13C-NMR data of these compounds clearly show that the equilibrium lies completely on the side of the 2H-pyran. In contrast, the reaction of 1 with 1,3-indandione yielded the ring-opened dienone derivative as a mixture of E and Z isomers.
本研究讨论了甲
硫基、乙
硫基或苄基
硫代二苯环
丙烯鎓离子(1)与 5、6 和 7 元环 1,3-二酮的反应,从而得到 2-烷
硫基-
2H-吡喃或二烯酮衍
生物。在
三乙胺存在下,用
1,3-环戊二酮、
1,3-环己二酮、
5,5-二甲基-1,3-环己二酮、
4-羟基-6-甲基-2-吡喃酮、
4-羟基
香豆素和
1,3-环庚二酮处理 1,可得到 2-烷
硫基-
2H-吡喃。根据元素分析、红外光谱、1H-NMR、13C-NMR 和质谱数据以及
化学转化,阐明了这些产物的结构。在醇中加入
氯化
汞(II)的 2-烷
硫基-
2H-吡喃会转化为相应的 2-烷氧基-
2H-吡喃。这些化合物的 1H- 和 13C-NMR 数据清楚地表明,平衡完全在 2H-pyran 一侧。相反,1 与 1,3-
茚二酮反应生成的开环二烯酮衍
生物是 E 和 Z 异构体的混合物。