One such modification is to conduct the substitution reaction in a strong acid, converting –OH to –OH 2(+). Because the hydronium ion (H 3 O (+)) is a much stronger acid than water, its conjugate base (H 2 O) is a better leaving group than hydroxide ion.

2018年1月29日 · Today we’ll describe the two main patterns by which various substituents “ direct ” electrophilic aromatic substitution. In one pattern, substituents direct the reaction to give either the “ ortho ” (1,2) or “ para ” product, with a slight preference for “para” (1,4).

2018年10月20日 · Facts I know: 1) More the electron density in benzene ring, the faster the reaction. 2) Lone pair on -OCH3 group undergoes resonance and makes ortho-para positions electron rich, and so does -CH3 by hyperconjugation. 3) -OCH3 group shows -I (electron withdrawing) and -CH3 shows +I (electron releasing).

甲氧基，为 甲醇 分子中去掉羟基上的 氢原子 后，剩下的一价基团， 结构式 为：CH3O-。 是最简单的一种烷氧基。 可以看成甲基醚的一部分，是一种供电子基。 主要用途：作为医药和染料的中间体，也用于食品工业制取 香兰素 等。 对眼睛、粘膜、 呼吸道 及皮肤有刺激作用。 唇及皮肤可能因缺氧而青紫。 吸入、摄入或经皮肤吸收均对身体有害。 可引起呼吸系统疾病。 有机物命名法. 一般规则. 取代基的顺序规则. 当主链上有多种取代基时，由顺序规则决定名称中基团的先后顺 …

There are 3 steps to solve this one. Several methods can achiev... Answer to How to add och3 to a benzene?

2017年9月26日 · Activating and Deactivating Groups in Electrophilic Aromatic Substitution. The rate of electrophilic aromatic substitution (EAS) reactions is greatly affected by the groups attached to the ring. The more electron-rich the aromatic ring, the faster the reaction. Groups that can donate electron density to the ring make EAS reactions faster.

将基团加上一个 氢原子 （-H）或者羟基（-OH）使之构成一个中心元素的 化合价 为常用的分子，如此以来，分子呈中性，氢原子显正电，羟基显负电，剩下的基团所表现出的电性就可以判断了。 基团的优先顺序： 1、原子： 原子序数 大的排在前面， 同位素 质量数大的优先。 几种常见原子的优先次序为：I>Br>Cl>S>P>O>N>C>H。 2、饱和基团：如果第一个原子序数相同，则比较第二个原子的原子序数，依次类推。 常见的烃基优先次序为：（CH3）3C->（CH3）2CH …

2018年2月2日 · Case Study #1: An ortho-,para- Director (OCH3) Electrophilic aromatic substitution of methoxybenzene tends to give ortho- and para- products with very little meta- . Here’s what happens in nitration, for example:

2025年2月18日 · Choose the correct answer from the options given below : (1) (A), (C) and (D) only. (2) (A), (B) and (E) only. (3) (A) only. (4) (A) and (C) only. (B) –CN is meta directing But –OH is ortho / pera directing. (E) Halides are deactivating groups.

Chained Alkene: add OCH3 to most substituted carbon with stereochemistry + enantiomer