A process for the preparation of an 1,1-disubstituted oxirane is disclosed, wherein an organic sulphide is reacted in a polar solvent with an educt containing a leaving group attached to a primary or secondary carbon atom, and/or the sulfonium salt formed in this way is reacted with a ketone in presence of a base and a polar solvent. Oxiranes of the type obtained may be further converted into the corresponding α-hydroxyketone or α-aminoketone, either in one step by subjecting to aerobic oxidation in the presence of a transition metal catalyst, or in two steps by hydrolyzation in the presence of an aqueous acid to the corresponding dialcohol and subsequent selective oxidation. Further described are some novel epoxide intermediates. The α-hydroxyketones and α-aminoketones thus obtainable are useful inter alia as photoinitiators.
本发明公开了一种制备1,1-二取代环
氧烷的方法,其中有机
硫化物在极性溶剂中与含有一个离去基团连接到一级或二级
碳原子的底物反应,和/或以碱和极性溶剂存在下,以这种方式形成的磺鎓盐与
酮反应。所获得的类型的环
氧烷可以进一步转化为相应的α-羟基
酮或α-
氨基
酮,可以通过在过渡
金属
催化剂存在下进行空气
氧化一步完成,也可以通过在
水酸存在下
水解为相应的二元醇并进行选择性
氧化两步完成。还描述了一些新的环
氧中间体。因此获得的α-羟基
酮和α-
氨基
酮可用作光
引发剂等。