Bromination of the acetals 4 derived from aryl alkyl ketones, ArCOR, and (2R,3R)-tartaric acid results in bromoacetals 5 with 78–90% de. Hydrolysis of those compounds with Ar = 4-methoxyphenyl or 3-bromo-4-methoxyphenyl results, after recrystallisation, in α-bromoketones 8 with 66–98% ee which are shown to undergo the Baeyer–Villiger oxidation to α-bromoesters 9 with minimal racemisation. α-Bromoketone
溴化 的
缩醛 4衍生自芳基烷基酮,ArCOR和(2 R,3 R)-
酒石酸产生
溴缩醛5的de-含量为78-90%。
水解 取Ar = 4-
甲氧基苯基或3-溴-4-
甲氧基苯基的那些化合物 重结晶,在ee含量为66-98%的α-
溴代酮8中,已显示出其经过Baeyer-Villiger氧化成α-
溴代酸酯9的消旋作用极小。α-
溴酮8d被证明经历了羰 减少到苏式-
溴代醇15并保留立体
化学。