High polarity, strong intermolecular force, high melting and boiling point

Soluble with each other, the molecular weight increases and decreases

Stronger than carbonic acid, affected by R group

Reacts with carbonate to produce CO2

acid halide

Anhydride

ester

Amides react with ammonia or organic amines at room temperature to form ammonium salts, which can be heated and dehydrated to form amides.

Carbon reduction is easy to occur when α-C is connected with an electron-withdrawing group.

Classification

Gradually replaced by halogen under the action of phosphorus

Lithium aluminum hydride LiAlH4

Diborane B2H5

Fehling's reagent can be used to identify

Can be oxidized to CO2 by potassium permanganate

Sulfate plus magnesium

Sulfuric acid plus zinc

α

β

γ

...

It has both carboxylic acid properties and alcohol properties.

physical properties

chemical properties

P182

Salicylic acid (ortho-hydroxybenzoic acid)

paraben

gallic acid

α-Keto acids are deacidified under the action of dilute sulfuric acid to form aldehydes

Beta-keto acids generate ketones

Sodium tetrahydroborate

Tetrahydrogen lithium aluminum

Aldehydes can be oxidized to dicarboxylic acids

Keto acids are difficult to oxidize. After decarboxylation to aldehydes, α-keto acids are oxidized to carboxylic acids with one less carbon atom than the keto acids.

Without α-H, Cannizzaro reaction can occur

Reducible Toulon's reagent

Low molecular weight is a liquid, high molecular weight is a solid

hydrolysis

Alcoholysis

Amine (ammonolysis)

Influencing factors

Preparation of primary amines with one less carbon atom

Amide generation

protecting group

α-H is weakly acidic and reacts under the action of strong bases

Similar to aldol condensation, forming β-keto ester

-CH2 and -NH are greatly affected by the -I group and are highly acidic

π-π conjugation, stable

Intramolecular hydrogen bonding, cyclic chelates

and Na release H2

discolor bromine water

Color development with ferric chloride

nucleophilic substitution

Biuret reaction: reacting with dilute CuSO4 to produce purple-red color

Preparation method