Studies in Thio‐Claisen Rearrangement: Regioselective Synthesis of Thiopyrano[2,3‐<i>b</i>]pyran‐2‐ones and Thieno[2,3‐<i>b</i>]pyran‐2‐ones
作者:K. C. Majumdar、S. Sarkar、S. Ghosh
DOI:10.1081/scc-120030314
日期:2004.12.31
4‐Mercapto‐6‐methyl‐2‐pyrone was alkylated with different allylic and propargylic halides under phase transfer catalyzed condition in the presence of TBAB or BTEAC catalyst in chloroform–aqueous NaOH (1%) at room temperature. The S‐alkylated thiopyran‐2‐ones were then refluxed in quinoline or in chlorobenzene to give 4‐chloromethylthiopyrano[2,3‐b]pyran‐2‐one and 4‐hydroxymethylthiopyrano[2,3‐b]pyran‐2‐one or several
摘要 4-Mercapto-6-methyl-2-pyrone 在相转移催化条件下,在 TBAB 或 BTEAC 催化剂存在下,在氯仿 - NaOH 水溶液 (1%) 中,在室温下用不同的烯丙基和炔丙基卤化物烷基化。S-烷基化噻喃-2-酮然后在喹啉或氯苯中回流,得到4-氯甲基噻喃[2,3-b]吡喃-2-酮和4-羟基甲基吡喃并[2,3-b]吡喃-2-酮或几个噻吩并[2,3-b]吡喃-2-酮。