有机合成题是高考必考题型,解答此类题目的一般思路是“烃→卤代烃→醇→醛→酸→酯→……”。但在解答有机合成题时,仅运用常规方法还不够,有时还要运用一些“非常规”的策略。一、先消去后加成使官能团转换位置或数目增多一般都采取先消去后加成的方法,可以由醇或卤代烃先发生消去反应,再与HX、X_2或H_2O发生加成。例1在有机反应中,反应物相同而条件不同时,可以得到不同的产物。下边框图中的R代表烃基,副产物已略去。请写出由 Organic synthesis is the college entrance examination exam questions will be to answer such questions the general idea is “hydrocarbon → halogenated hydrocarbons → alcohol → aldehyde → acid → ester → ......”. However, in the process of answering organic synthesis questions, it is not enough to use only conventional methods, and sometimes some unconventional strategies are used. First, the elimination of post-addition functional groups to change the location or the number of increase are generally taken to eliminate the first post-addition method, you can alcohol or halogenated hydrocarbon elimination reaction occurred before re-HX, X_2 or H_2O addition occurs. Example 1 In an organic reaction, different reactants are obtained under the same conditions but different conditions. R in the bottom panel represents a hydrocarbyl group, by-products have been omitted. Please write by