两种1,1-二取代乙烯的简单合成

The Simple Synthesis Method of Two 1,1-Disubstituted Alkenes

5-亚甲基二苯并[a,e]-环庚烷(2a)和5-亚甲基二吡啶并[1,2-b:5,4-b']环戊烷(2b)分别应用两种不同的方法合成。方法一是通过酮与三苯基甲基溴化鳞反应(Wittig法)制备,方法二是通过酮与格氏试剂反应后再在酸性条件下发生消除反应制备。后者原料便宜,操作简单且产率高,是合成此类1,1-二取代乙烯的好方法。通过元素分析及NMR对产物的结构进行了表征。

5 - Methenedibenzo [ a, e ] - cycloheptane and 5 - Methylenedipyridine [ 2,1 - b ： 3,4 - b＇ ] - cyclopentane were synthesized by two different methods. One method was that ketones react with methyhriphenylphosphonium bromide （wittig reaction） to give target products （2a and 2b）. Another method was that Grignard reagent （methylmagnesium iodide） was used as nucleophilic reagent to react with ketones, then H2SO4 was dropped to eliminate H20 and the products（2a and 2b） were obtained. The latter way was better than the anterior way because material was cheaper and yield was higher. The products were characterized by elemental analysis and NMR spectroscopy.