ORIENTATION IN AROMATIC SUBSTITUTION .1. 1,2-DIMETHOXY-3-ISOPROPYLBENZENE AND 3,5-DIMETHYLANISOLE
ORIENTATION IN AROMATIC SUBSTITUTION .1. 1,2-DIMETHOXY-3-ISOPROPYLBENZENE AND 3,5-DIMETHYLANISOLE
复制标题
DOI：
10.1021/ja01596a071
复制
发表时间：
1956-01-01
影响因子：
15
通讯作者：
CASHAW, JL
中科院分区：
文献类型：
--
作者：
EDWARDS, JD;CASHAW, JL
报道了在研究L、2-二甲氧基-3-异丙基苯和3，5-二甲基苯甲醚的亲电取代反应中发现的一些反常取向。显然，在这些芳香族体系中，不同位置的电子利用率差别很小，空间位阻可能成为决定取向的主要因素，取向由进入基团的大小和形状决定。在一些研究的继续中，1，2-二甲氧基-3-异丙基苯(I)遇到了一些反常的取向。I的硝化反应得到1，2-二甲氧基-3-异丙基-5-硝基苯(II)。3·4研究了I的溴化反应。以1-甲氧基-2-乙酰氧基-3-异丙基-3-异丙基苯为原料合成了2-二甲氧基-3-异丙基-4-溴苯，产率较高，与以1-甲氧基-2-乙酰氧基-3-异丙基苯为原料合成的产物相同。通过已发表的步骤4将化合物III转化为3，4-二甲氧基-2-异丙基苯甲酸(IV)。
Some anomalous orientations found in a study of electrophilic substitution reactions of l, 2-dimethoxy-3-isopropylbenzene and 3, 5-dimethylanisole are presented. Apparently, the difference in electron availability at various positions in these aromatic systems is small and steric hindrance can become thedominating factor with the orientation being determined by the size and the shape of the entering group.In continuation of certain studies, 1· 2 some anomalous orientations were encountered in 1, 2-dimethoxy-3-isopropylbenzene (I). It has been shown conclusively that nitration ofI gives 1, 2-dimethoxy-3-isopropyl-5-nitrobenzene (II). 3· 4 The bromination of I has now been studied. A good yield of l, 2-dimethoxy-3-isopropyl-4-bromobenzene (III) was formed and shownto be identical with that prepared by an unequivocal synthesis4 from 1-methoxy-2-acetoxy-3-isopropylbenzene. Com-pound III was converted by the published procedure4 to 3, 4-dimethoxy-2-isopropylbenzoic acid (IV).