Regioselective Synthesis of Quinolin-8-ols and 1,2,3,4-Tetrahydroquinolin-8-ols by the Cyclization of 2-(3-Hydroxyphenyl)ethyl Ketone<i>O</i>-2,4-Dinitrophenyloximes
作者:Katsuya Uchiyama、Ayako Ono、Yujiro Hayashi、Koichi Narasaka
DOI:10.1246/bcsj.71.2945
日期:1998.12
Cyclization of 2-(3-hydroxyphenyl)ethyl ketone O-2,4-dinitrophenyloximes proceeds on the oxime nitrogen atom by the treatment with NaH and then with 2,3-dichloro-5,6-dicyano-p-benzoquinone and acetic acid to yield quinolin-8-ols regioselectively. The reaction in the presence of Na[BH3(CN)] affords 1,2,3,4-tetrahydroquinolin-8-ols. The present cyclization proceeds via alkylideneaminyl radical intermediates
2-(3-羟基苯基)乙基酮 O-2,4-二硝基苯基肟的环化反应在肟氮原子上进行,先用 NaH 处理,然后用 2,3-二氯-5,6-二氰基-对苯醌和乙酸处理区域选择性地产生喹啉-8-醇。在 Na[BH3(CN)] 存在下反应得到 1,2,3,4-四氢喹啉-8-醇。本环化通过亚烷基亚胺基自由基中间体进行,该中间体由 3-羟基苯基和 2,4-二硝基苯基部分之间的单电子转移产生。