同分异构现象是有机化合物种类繁多、数量巨大的原因之一。同分异构体的知识贯穿于中学有机化学的始终。同分异构体种类的确定是学习有机化学的一大特点,也是高考中有关有机化学部分必考内容。从近几年全国各省市高考化学试题中有关同分异构体的命题形式来看,大都以苯环上取代产物为中心,拓展考查同分异构体种类的判断与书写。这类同分异构体种类数目往往较大,考场时间紧张,不可能一一写出,因而,应 Isomerism is one of the reasons for the large variety and large number of organic compounds. Isomers of knowledge throughout the organic chemistry in secondary school always. The determination of the types of isomers is a major feature of learning organic chemistry, but also the college entrance examination in the organic chemistry part of the necessary test content. Judging from the propositions of the isomers in chemical examinations of college entrance examination in various provinces and cities in recent years, most of them take the substituted products on the benzene ring as the center and expand the examination and writing of the types of isomers. Such isomeric species tend to be large in number and time-consuming to test the exams and can not be written one by one, therefore,