Mal Dipakranjan, Roy Joyeeta, Biradha Kumar
Department of Chemistry, Indian Institute of Technology, Kharagpur-721302, India.
Org Biomol Chem. 2014 Nov 7;12(41):8196-203. doi: 10.1039/c4ob01309c. Epub 2014 Sep 8.
The anionic annulation of MOM-protected furoindolone with 4-bromoquinoline followed by deprotection of the N-MOM group provides calothrixin B, whereas that with 3-bromoquinoline yields isocalothrixin B. The outcomes are explained by the divergence of the reaction mechanism from commonly perceived quinolyne intermediate. A sequence of addition-cyclization-elimination is proposed to account for the formation of calothrixin from 4-bromoquinoline.
对甲氧基甲基（MOM）保护的呋喃吲哚酮与4-溴喹啉进行阴离子环化反应，随后对N-MOM基团进行脱保护，可得到卡罗硫辛B；而与3-溴喹啉反应则生成异卡罗硫辛B。这些结果可通过反应机理与通常认为的喹啉炔中间体的差异来解释。有人提出了一个加成-环化-消除序列来解释由4-溴喹啉形成卡罗硫辛的过程。
