硫酸奎宁-C14'的氧化。-硫酸奎宁(488mg)溶解在10%硫酸(10ml)中,加入二氧化锰(105mg)。将混合物升至沸点并在半小时内加入溶解在水(2毫升)中的三氧化铬(1.0克)。回流持续3小时。然后加入热水(90毫升)和15N氨(20毫升),静置18小时后。在蒸汽浴上借助硅藻土过滤混合物。残留物用热的稀氨溶液萃取数次。将合并的滤液蒸发至小体积(15毫升)并用乙酸酸化,得到奎宁酸(207毫克,83%)。奎宁酸的脱羧和 6-甲氧基喹啉的苯基化。-将干燥的奎宁酸 (205 毫克) 与亚铬酸铜催化剂混合"(205 毫克。) 和加热 (15) DJ Lussman, ER Kirch 和 OL Webster, J. Am。佛姆。副,设置。Ed., 40, 368 (1951)。
Diastereoselective synthesis of α-bromo amides leading to diastereomerically enriched α-amino-, α-hydroxy- and α-thiocarboxylic acid derivatives
作者:By Robert S Ward、Andrew Pelter、Dominique Goubet、Martyn C Pritchard
DOI:10.1016/0957-4166(95)00032-k
日期:1995.2
prepared diastereoselectively starting from racemic α-bromo acids, and undergo epimerisation under appropriate conditions leading to an enhanced d.e.. By reacting the individual isomers or the mixture of diastereoisomers with a suitable nucleophile it is possible to obtain α-substituted carboxylic acids, including α-amino- α-hydroxy- and α-thiocarboxylic acid derivatives, in diastereomerically enriched