Synthesis of cyclopentano[c]-s -triazoles by the intramolecular ring transformation of 1,3,4-oxadiazoles
作者:Tadashi Sasaki、Masatomi Ohno、Eikoh Ito、Koji Asai
DOI:10.1016/s0040-4020(01)96889-9
日期:1984.1
Cyclopentano[c]-s-triazoles were synthesized by intramolecular ring transformation starting from y-keto-l,3,4-oxadiazoles 5 and 9. The required functionality for this intramolecular reaction was established by (i) the reaction of lithiated 2-methyl-l,3,4-oxadiazole 4 with the methyl enol ether of α-bromo ketones followed by hydrolysis; (ii) reductive amination of γ-ketones 5 and 9 to further reorganized
通过从γ-酮-1,3,4-恶二唑5和9的分子内环转化合成环戊烷[c] -s-三唑。该分子内反应所需的官能度是通过(i)将锂化的2-甲基-1,3,4-恶二唑4与α-溴代酮的甲基烯醇醚反应,然后水解;(ii)用NaBH 3 CN将γ-酮5和9还原胺化为酰肼7和γ-氨基-1,3,4-恶二唑9 。和(iii)的热分解7和γ在280℃(5毫米汞)的环戊烷并[ c ^ ] - š -triazoles 8和11。通过相同的处理,S连接的类似物2提供了所需的稠合的s-三唑17。