有机化学（酯）

含氧无机酸和醇失水产物称为无机酸酯；有机羧酸和醇失水产物称为有机酸酯。

命名时，将酸的名称放在前，烃氧的烃基部分放在后，最后再加上酯。 

酯  ester

官能团  酯基

酸（羧酸或无机含氧酸）与醇反应生成的一类有机化合物叫做酯。

低级酯有香气挥发性液体，高级酯蜡状固体或很稠液体(有机上低级酯一般指含碳原子数少，而高级酯一般指含)

几种高级酯是脂肪的主要成分。(生物学)

酯和油脂的区别：

性质不同
酯：有机化学中 醇与羧酸或无机含氧酸发生酯化反应生成的产物。
油脂：油和脂肪统称。

油脂都是高级脂肪酸与甘油形成的酯。

1.油脂是烃衍生物。

2.油脂是一种特殊的酯。

4.油脂：油脂密度一般比水小，没有固定的熔沸点。

3.自然界中油脂混合物，主要成分是一分子甘油与三分子高级脂肪酸脱水形成的酯，称为甘油三酯。

5.油脂中的碳链含碳碳双键时（即为不饱和脂肪酸甘油酯），主要是低沸点的植物油；油脂中的碳链为碳碳单键时（即为饱和脂肪酸甘油酯），主要是高沸点的动物脂肪。

酯	低级酯
	高级酯
	特殊酯（油脂）

溶解性

酯类都难溶于水，易溶于乙醇和乙醚等有机溶剂，密度一般比水小。低级酯具有芳香气味液体。

低分子量酯无色、易挥发芳香液体

高级饱和脂肪酸单酯常为无色无味固体，高级脂肪酸与高级脂肪醇形成的酯为蜡状固体。

熔沸点一般规律

酯的熔点和沸点要比相应的羧酸低。

酯一般不溶于水，能溶于各种有机溶剂。低分子量的酯可以作许多有机化合物的溶剂，也可作清漆的溶剂。 

 酯是中性物质。

 The dehydrated products of oxygenated inorganic acids and alcohols are called inorganic acid esters; The dehydration products of organic carboxylic acids and alcohols are called organic esters.

When naming, put the name of the acid in front, the hydrocarbon radical part of the hydrocarbon oxygen in the back, and finally add the ester.

Ester ester

Functional ester group

Saturated monoester

Cnh2no2 (n ≥ 2, n is a positive integer)

General formula

R-COO-R'

A class of organic compounds formed by the reaction of acids (carboxylic acids or inorganic oxygenated acids) with alcohols are called esters.

Lower ester has aroma, volatile liquid, and higher ester is a waxy solid or very thick liquid (organic upper and lower esters generally refer to those with few carbon atoms, while higher esters generally refer to those with)

Several higher esters are the main components of fat. (Biology)

Solubility

Esters are insoluble in water, easily soluble in organic solvents such as ethanol and ether, and their density is generally lower than that of water. Lower ester liquid with aromatic odor.

Low molecular weight ester colorless and volatile aromatic liquid

Higher saturated fatty acid monoesters are usually colorless and tasteless solids, and the esters formed by higher fatty acids and higher fatty alcohols are waxy solids.

General rule of melting boiling point

The melting point and boiling point of esters are lower than those of corresponding carboxylic acids.

Esters are generally insoluble in water and can be dissolved in various organic solvents. Low molecular weight esters can be used as solvents for many organic compounds and varnishes.

Esters are neutral substances.

The hydrolysis of ester is more difficult than that of acyl chloride and anhydride, so it must be catalyzed by acid or base.

Many natural fats, oils or waxes can be hydrolyzed to produce corresponding carboxylic acids. The higher fatty acid sodium produced by alkaline hydrolysis of oils and fats is soap. The alcoholysis reaction of esters is the reaction in which the alkoxy group in the ester is replaced by the alkoxy group of another alcohol. The reaction must be carried out under the catalysis of acid or alkali. This reaction is often used to change from one kind of ester to another.

Esters can be catalytically reduced to two molecules of alcohols. The most widely used catalyst is copper chromium oxide. The reaction is carried out under high temperature and high pressure. If the molecules contain carbon carbon double bonds, they can be reduced at the same time.

The ester reacts with Grignard reagent to synthesize tertiary alcohol with two same substituents.

Hydrolysis of esters

The hydrolysates of esters in acidic and alkaline environments are different. Alcohols (or phenols) and acids are formed under acidic conditions. Alcohols (or phenols) and carboxylates are formed in alkaline environment.