大连理工有机化学{双语}

编著与制作： 南华大学 邓健
19
The position of the equilibrium between gem diols and aldehydes / ketones depends on the structure of the carbonyl compound.
+
H OH H NH-NH2 XMg R''
编著与制作： 南华大学 邓健
1. React with HCN (hydrocyanic acid)
Aldehydes and ketones react with HCN to produce cyanohydrins (氰醇). The nucleophilic cyanide ion adds to the electrophilic carbonyl carbon.
Nucleophilic oxygen reacts - with acids and electrophiles
O ——C———C H
(2) Activity of -hydrogen
+ (1) Electrophilic carbon reacts with bases and nucleophiles
OH R C H( CH3 ) CN 氰醇
This reaction is only suitable to the aldehydes, alkyl methylketones, and cycloketones (C≤8) (醛、脂肪族甲基酮、8C以下环酮适用)
H
activity
H
C=O
> H C=O > (
CHO
CHO
Cyclohexanecarbaldehyde 2-Naphthalenecarbaldehyde 环己基甲醛 2-萘甲醛 (3) Aromatic aldehydes are also named as derivatives of the parent benzaldehyde. benzaldehyde
+
O
C
H H ( :Nu H H H
-
： CN ： SO3Na ) ： OR H+ ： OH + (E ) ： NH-G
O-H C
Nu
XMg： R Cyanide ion(CN-), bisulphite anion, alcohols, H2O, ammonia and carbon anions (R3C-) are several of many possibilities.
CHO
O C- CH 3
2
编著与制作： 南华大学 邓健
Ⅱ. Nomenclature
1. Aldehydes
(1) The IUPAC names for aldehydes are derived from the parent hydrocarbon by identifying the longest chain containing the aldehyde group (-CHO) and replacing the ‘-e’ ending with ‘-al’.
O CH3
3-Methylcyclohexanone
(3) Ketones in which the carbonyl group is attached directly to a benzene ring are named as phenyl derivatives of the corresponding aliphatic carbonyl compound.
CH3 O O CH3CH CHC H 4 3 2 1 2-Butenal
编著与制作： 南华大学 邓健 3
CH3CHCH2CH2C H 5 4 3 2 1 4-Methylpentanal
(2) For more complex aldehydes in which the –CHO group is attached to a ring, the suffix –carbaldehyde is used.
第 9 章 醛 和 酮
Chapter 9 Aldehydes and Ketones
Sec 1
Classification & Nomenclature
Sec 2 Structure Sec 3 Properties
编著与制作： 南华大学 邓健 1
Sec 1 Classification & Nomenclature
OH O + H or OH A gem R C R'(H) O H R C R'(H) + 2 diol OH
The reaction is reversible, and a gem diol can eliminate water to regenerate a ketone or aldehyde.
O-CH3 C—H O-CH3 + H2O
The reaction of ketone with alcohol is slower than aldehyde’s, but cyclic acetal is easily formed.
CH3
dry HCl CH3 O HO An cyclic C O+ C acetal CH3 HO CH3 O Ethylene glycol Acetone ethylene ketal
(H)
(3) The aldehyde H will be lost easily
编著与制作： 南华大学 邓健
8
Ⅰ. Nucleophilic Addition (亲核加成)
The most common reaction of aldehydes and ketones is the nucleophilic addition reaction, in which a nucleophile (:Nu or :Nu-) adds to the electrophilic carbon of the carbonyl group.
O CH3CH2CH2CCH3 O CH2=CHCCH2CH2CH3
5
4
2 1
1
3
6
2-Pentanone 2-戊酮
O CH3 C O CH2 C CH3
1-Hexen-3-one 1-己烯-3-酮
2,4-Pentanedione 2,4-戊二酮
5
编著与制作： 南华大学 邓健
(2) Cyclic ketones are named with the carbonyl group occupying the 1-position in the ring.
O R—C—H
+ 2 HO—R’
dry HCl
OR' H R C
+ H2O
OR'
1,1-Dialkoxyalkane (Acetal, 缩醛)
编著与制作： 南华大学 邓健 15
O CH3C－H ＋EtOH
Acetaldehyde
OH
dry HCl
CH3－C－OEt
EtOH
OEt CH3－C－OEt
CHO
CHO
1 2 3
Benzenecarbaldehyde Benzaldehyde 苯甲醛
4
4-Bromobenzaldehyde (p-Bromobenzaldehyde)
Br
2. Ketones
(1) In the IUPAC system, ketones are named by identifying the longest chain containing the carbonyl group and replacing the ‘ –e ’ with ‘–one.
编著与制作： 南华大学 邓健
R
)
>
CH3 C=O R
13
2. React with sodium bisulphite (NaHSO3)
O R —C — H
+
OH :S—O- Na+ O
ONa R — C—H SO3H
OH R—C—H SO3Na
α-Hydroxysodium sulfonate α-羟基磺酸钠
H HO-CH2-CH2-CH2-C=O

OH
H 89%
H HO-CH2-CH2-CH2-CH2-C=O

OH
H 94%
编著与制作： 南华大学 邓健
18
4. React with H2O: Hydration
Aldehydes and ketones undergo nucleophilic addition with water to yield 1,1-diols, or geminal (gem) diols.
H Acetaldehyde ethyl hemiacetal
H HOH Acetaldehyde diethyl acetal
O C—H + CH3OH NO2
H2SO4
(trace) NO2 76~65% 3-Nitrobenzaldehyde dimethyl acetal
3-硝基苯甲醛二甲基缩醛
编著与制作： 南华大学 邓健 9
Mechanism of Nucleophilic Addition
Nu：
(—）
slow

H+
Nu
H
Nu
fast
Step 1 is the slowest, so this reaction is called as nucleophilic addition.