carbonyl compounds

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Carbonyl compounds Acid anhyd ride 酸酸 Amides 酸酸 Carboxylic acids 酸酸 Acid chlori des 酸酸 Aldehydes Esters Ketones general formula class general formula class R O R' R O H R O OH R O OR' R O Cl R O NR 1 R 2 R O O R O

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Carbonyl compounds. class. general formula. class. general formula. Ketones 酮. Esters 酯. Aldehydes 醛. Acid chlorides 酰卤. Carboxylic acids 羧酸. Amides 酰胺. Acid anhydride 酸酐. Chapter 10 Aldehydes and Ketones. Text 1: p 774-835 Text 2: p 311-348. - PowerPoint PPT Presentation

TRANSCRIPT

Page 1: Carbonyl compounds

Carbonyl compounds

Acid anhydride 酸酐

Amides

酰胺Carboxylic aci

ds 羧酸

Acid chlorides

酰卤Aldehydes

Esters

酯Ketones

general formula

classgeneral formula

class

R

O

R'

R

O

H

R

O

OH

R

O

OR'

R

O

Cl

R

O

NR1R2

R

O

O R

O

Page 2: Carbonyl compounds

Chapter 10 Aldehydes and Ketones

Text 1: p 774-835

Text 2: p 311-348

Page 3: Carbonyl compounds

Structure of the carbonyl group

C O

120o

120o

120o

1. C-sp2 hybridization

2. The bond angles is 120o.

3. It is a trigonal planar structure

4. The carbon-oxygen double bond consists of a sigma bond and a pi-bond

C O C O

Resonance structures

Page 4: Carbonyl compounds

CHO

Benzaldehyde

(from bitter almonds)

苯甲醛 ( 苦杏仁 )

CHO

OH

OCH3

Vanillin

(from vanilla beans)

香草醛 ( 香草豆 )

CHO

OH

Salicylaldehyde

(from meadowsweet)

水杨醛 ([ 植 ] 绣线菊 )

CH=CHCHO

Cinnamaldehyde

(from cinnamon)

肉桂醛 (3- 苯基丙烯醛) ([ 植物 ] 肉桂 , 桂皮 )

CHO

O

O

Piperonal

(made from safrole;

odor of heliotrope)

胡椒醛由黄樟油精制备 ,

[ 植 ] 向日葵气味

Page 5: Carbonyl compounds

O

Camphor

樟脑

O

*

Carvone 香芹酮( - )薄荷味( + )香菜味 O

Muscone

麝香酮

CH3

O

Acetophenone

苯乙酮乳香味

Page 6: Carbonyl compounds

10.1 Nomenclature of aldehydes and ketones

IUPAC names common names

aldehydes: alkane — alkanal ---ic acid—---aldehyde

ketones: alkane — alkanone alkyl alkyl ketone

H C

O

H H3C C

O

H CH3CH2CHO CH3CH2CH2CHO

Methanal甲醛formaldehyde

Ethanal乙醛acetaldehyde

Propanal丙醛propionaldehyde

Butanal丁醛butyraldehyde

(formic acid) (acetic acid) (propionic acid) (butyric acid)

Page 7: Carbonyl compounds

CH3 CH2 CH CH C

O

H

2-pentenal (pent-2-enal)2- 戊烯醛

benzenecarbaldehyde苯甲醛benzaldehyde

C

O

H

cyclohexanecarbaldehyde环己烷(基)甲醛

C

O

H

2-Naphthalenecarbaldehyde2- 萘甲醛

CHO

CH3CHCH2CHO

Br

3-bromobutanal3- 溴丁醛β-bromobutyraldehyde

Page 8: Carbonyl compounds

H3C

O

CH3

2-propanoneacetone丙酮dimethyl ketone

H3C

O

CH2CH3

2-butanone (butan-2-one)2- 丁酮methyl ethyl ketone

CH3COCH2CH=CH2

4-penten-2-one

4- 戊烯 -2- 酮

CH3CH2 C

O

CH2 CHO

3-oxopentanal

3- 氧代戊醛

Page 9: Carbonyl compounds

C

O

benzophenone

(diphenyl ketone)

二苯甲酮

C

O

OH

CHO

2-formylbenzoic acid

2- 甲酰基苯甲酸

H3C C

O

SO3H

4-acetylbenzenesulfonic acid

4- 乙酰基苯磺酸

C

O

CH3

acetophenone

(methyl phenyl ketone)

苯乙酮

Page 10: Carbonyl compounds

10.2 Physical properties of aldehydes and ketones

Boiling point:

alkane < ether < aldehyde< ketone < alcohol

Solubility in water:

acetone, ethanal are misible (混溶) with water (hydrogen bond)

formaldehyde: 40% aqueous solution (formalin, 福尔马林 )

O

O

OH C H

O

3H+

(gas)

heat

mp: 62 °C

O

O

O

H3C C H

O

3H+

heat

bp: 125 °C

H3C H

CH3

H

H

H3C

bp: 21 °C

trioxane

三聚甲醛paraldehyde

三聚乙醛

Page 11: Carbonyl compounds

10.3 Spectroscopy of aldehydes and ketones

C=O ~1710 cm-1 (O=)C-H 2720, 2820 cm-1

C C C

O

~1685 cm-1

O OO O

ν: 1714 1745 1790 1815 cm-1

n-π*, weak, 280~300 nm;

π -π*, strong, < 200 nm; C=C-C=O, >200 nm

IR

UV

Page 12: Carbonyl compounds

1H NMR: CH2 C CH2

O

δ: 2.4 2.1 9~10CH3 C

O

C H

O1H NMR

13C NMR C=O: ~200 ppm, α-C: 30~40

17

CH3CH2CH2COCH3

209 42

30

14

Page 13: Carbonyl compounds

MS 43

86 71 58

CH3CH2CH2COCH3

γ-H is needed;

m/e: even (偶数 )

O

CCH2

CH2

CH2

H

CH3H3C

CCH2

OH

+CH2

CH2

M = 28

R C O R C O( 1 )

Mclafferty rearrangement ( 麦氏重排 )( 2 )

Page 14: Carbonyl compounds

10.4 Synthesis of aldehydes and ketones

R CHOH[ O ]

R C

2o alcohol ketone

R' R'

O

R CH2OH[ O ]

R CHO R COOH

1o Alcohol Aldehyde Carboxylic acid

[ O ]

1. Aldehydes and ketones from oxidation of alcohols

Oxidants: K2Cr2O7 or Na2Cr2O7 / H2SO4

CrO3/ H2SO4

PCC (Pyridinium chlorochromate, 吡啶三氧化铬 )

PDC (Pyridinium dichromate, 重铬酸吡啶盐 )

Page 15: Carbonyl compounds

2. Aldehydes and ketones from ozonolysis of alkenes

( 2 ) Zn, H2O reduction

R

R'

R''

H

( 1 ) O3, CH2Cl2, -78oC R

R'O O

R''

H+

Aldehydes (È©)

ketones (ͪ £©

Page 16: Carbonyl compounds

3. Aldehydes and ketones from alkynes

HC CH + H2OHgSO4,H2SO4 CH

OH

CH2 CH3 C H

O

R C C HSia2BH

C C

H

R H

BSia2

Sia = CHHC

H3C

H3C

CH3

H2O2 C C

H

R H

O H

C C

H

R H

O

H

OH

Page 17: Carbonyl compounds

4. Aromatic aldehydes and ketones from acylation of benzene derivatives

+ RCOClAlCl3 COR

+ HCl

+ AlCl3 COR+ HCl

O

R

O

RO

G

+ HCl + COAlCl3, CuCl

G

CHO

Gatterman-Koch formylation ( 盖特曼 - 考赫甲酰化反应 )

Friedel-Crafts acylation

Page 18: Carbonyl compounds

5. Synthesis of aldehydes and ketones using 1,3-dithiane

S S

H H

(1) BuLi(2) 1° R-X S S

R H

(1) BuLi(2) 1° R'-X S S

R R'

H3O+, HgCl2 H3O+, HgCl2

R H

O

R R'

O

(H)RC

(H)RO +

H+

- H2OSH SHS S

(H)R R(H)

1,3- dithiane

1,3- 二噻烷(硫缩醛)

Page 19: Carbonyl compounds

6. Synthesis of ketones from carboxylic acids

R C

O

OH

LiOH(or R'-Li)

R C

O

OLi R'-Li

R C

OLi

OLi

R'carboxylic acid

H3O+

R C

OH

OH

R'

-H2OR C

O

R'

ketone

hydrate 水合物

R C

O

OH

carboxylic acidR C

O

R'

ketone

Page 20: Carbonyl compounds

7. Synthesis of aldehydes and ketones from acid chlorides

R C Cl

O

R C R' (H)

O

R C Cl

O

R C H

OLiAlH(O-t-Bu)3

R C Cl

O

R C R'

OR'2CuLi Not RMgX

Not LiAlH4

Page 21: Carbonyl compounds

8. Synthesis of ketones from nitriles ( 腈 jing)

R C N + R'MgX R C

N+ MgX-

R'H3O+

R C

O

R'

R C N + R' Li R C

N+ Li-

R'H3O+

R C

O

R'

R C N R C

O

R'

nitrile

Page 22: Carbonyl compounds

9. Other methods

CH3

MnO2£¬65% H2SO4

CHO

ArCH32Cl2hv

ArCHCl2H2O ArCHO

ArCH3CrO3£¬£¨ CH3CO)2O

ArCH(OCOCH3)2

H2O ArCHO

……………………

Page 23: Carbonyl compounds

Assignments

Problem 18-1, 7, 8, 9, 11

Page 24: Carbonyl compounds

10.5 Reactions of aldehydes and ketones

Nucleophilic addition to the carbon-oxygen double bondReduction and oxidation of aldehydes and ketonesReactions of α-H

R C C

O

R'

H Nuacidity

Page 25: Carbonyl compounds

1. Nucleophilic addition to the carbon-oxygen double bond

RC

R'O + H-Nu

R

CR'

OH

Nu

Nucleophilic atom: C (carbon)

O (oxygen)

N (nitrogen)

S (sulfur)

Page 26: Carbonyl compounds

1). Carbon as nucleophilic atom

( 碳为亲核性原子 )

(1) organometallic reagents addition to C=O

+C6H5MgBr(1) Et2OH3C

CH

O(2) H3O+ C6H5CHOH

CH3

C C

R1

R2

OHCR H3O+

alkynol ( 炔醇 )

C O

R2

R1

R C CNa + C C

R1

R2

OCR Na

Page 27: Carbonyl compounds

(2) The Wittig reaction: the addition of ylide ( 叶立德 ) (18-13)

魏悌希反应

The wittig reaction has proved to be a valuable method for synthesizing alkenes. Wittig was a co-winner of the Nobel prize for chemistry in 1979.

C O

R

(R')H

+ (C6H5)3P-CHR'''

R''

Phosphorus ylideÁ×Ò¶Á¢µÂ

C CR

(R')H

R''

R'''+ O P(C6H5)3

Triphenylphosphine oxideÈý±½»ùÑõì¢

aldehyde ketone

the Wittig reagentalkene

Page 28: Carbonyl compounds

Preparation of phosphorus ylides:

Mechanism:

(C6H5)3P + CH2 Br (C6H5)3P CH2BrR

R

Betaine £¨ÄÚÑΣ©Phosphorus ylide Á×Ò¶Á¢µÂ

(C6H5)3P CHR (C6H5)3P CHRn-BuLi

-HBr

O+(C6H5)3P CH2 CH2

O P(C6H5)3

CH2

O P(C6H5)3

CH2+O P(C6H5)3

Methylenecyclohexane

1° RX are prefered

Page 29: Carbonyl compounds

Problem 18-14

Trimethylphosphine is much less expensive than triphenylphosphine. Why is trimethylphosphine unsuitable for making most phosphorus ylides?

Problem 18-15

(C6H5)3P +

OH3C

H

H

CH3

Predict the products. What is the stereochemistry of the double bond in the product?

Page 30: Carbonyl compounds

(3) The addition of hydrogen cyanide (HCN)

Cyanohydrins

腈醇 , α- 羟基腈

C O + H CN C

OH

CN

O

CCH3H3C

NaCN, H2SO4

OH

CCH3H3C

CN

Page 31: Carbonyl compounds

Cyanohydrins are useful intermediates in organic synthesis.

C

OH

CN

[H]

HCl, H2O

-H2O

C

OH

CH2NH2

C

OH

COOH

CC COOHH2SO4, heat

β-amino alcohol

β- 氨基醇

α-hydroxy acid

α- 羟基酸

α,β-unsaturated acid

α,β- 不饱和酸

Page 32: Carbonyl compounds

C O

H3C

H3C

+ HCN C

H3C

H3C

OH

CN

Cyanohydrinsëæ¼ÇâÇèËá

Hydrogen cyanide

HCl, H2OC

H3C

H3C

OH

COOH

a - Hydroxy acid

a - ôÇ»ùËá

H2SO4

CH3OHCH2C

CH3

COOCH3

- Unsaturated acid ester

CH2 C

CH3

COOCH3

* *n

¾Û±ûÏ©Ëá¼×õ¥2-¼×»ù±ûÏ©Ëá¼×õ¥

For example

Page 33: Carbonyl compounds

2). Oxygen as nucleophilic atom

( 氧为亲核性原子 )

(1) The addition of water to aldehydes and ketones: formation of hydrates( 水合物 )

Hydrate

( a gem-diol) 同碳二醇

RC

R'O +

R'

CR OH

OH

H-OHH+ or -OH

How about the mechanisms ?

Catalysis: acid or base

Reversible reaction

可逆反应 unstable

Page 34: Carbonyl compounds

(2) The addition of alcohols to aldehydes and ketones: Formation of Acetals( 缩醛(酮) )

OHCC=O

ROH, H+ OR +ROH, H ORC

OR+ H2O

hemiacetal 半缩醛 ( 酮 )

acetal 缩醛 ( 酮 )

Catalysis: acid

Reversible reaction

可逆反应

Old use: acetal 缩醛 ketal 缩酮IUPAC: acetal

Page 35: Carbonyl compounds

C=O C=OH+

H+ ROH OR

COH

H

++H OR

COH

OHC

OR +H ORC

OHH

+

H2OOR

C+ROH

ORC

OR

H

+

H+

ORC

OR

Mechanism

Hemiacetal 半缩醛 ( 酮 )

acetal 缩醛 ( 酮 )

Base (-OH) can not catalyze the acetal form

ation. Why?

SN1

Page 36: Carbonyl compounds

Cyclic acetals ( 环状缩酮 ) often have more favorable equilibrium constants than acyclic acetals.

RC

RO +

HCl RC

R

HO

HO O

O

+ H2O

RC

RO

O HCl+ H2O

RC

RO +

HO

HO

CH3CH2CHO + 2 CH3OHH+

H3CH2CHCOCH3

OCH3+ H2O

For example

Page 37: Carbonyl compounds

Use of acetals as protecting groups (保护基) .

C CH(CH2)2CHCH2CHO

CH3

H3C

H3C

CH3OH , H+

C CH(CH2)2CHCH2CH(OCH3)2CH3

H3C

H3C

HCl , H2OHOOC(CH2)2CHCH2CHO

CH3

HOOC(CH2)2CHCH2CH(OCH3)2

CH3

KMnO4

H

Example 1

C CH(CH2)2CHCH2CHO

CH3

H3C

H3C

HOOC(CH2)2CHCH2CHO

CH3

Page 38: Carbonyl compounds

CH3COCH2CH2Br CH3COCH2CH2CHCH3

OH

CH3COCH2CH2BrOH OH

H+ CH3CCH2CH2Br

O O

Mg , Et2O

CH3CCH2CH2MgBr

O O1. CH3CHO

2. H2O , H+

CH3COCH2CH2CHCH3

OH

Example 2

Page 39: Carbonyl compounds

O

O

OCH2CH3O CH2OH

Example 3

O

O

OCH2CH3

HO

HO

HCl

O

OCH2CH3

O

O

1. LiAlH4, (CH3CH2)2O

2. H2OCH2OH

O

O

H+

H2O

O CH2OH

Page 40: Carbonyl compounds

3). Nitrogen as nucleophilic atom( 氮为亲核性原子 )

NH2—H ammonia 氨NH2—R amine 胺 NH2—OH hydroxylamine 羟氨NH2—NH2 hydrazine 肼NH2—NHCONH2 semicarbazine 氨基脲

R'C

R''O + H2N G

R'C

R''N G + H2O

H+

Page 41: Carbonyl compounds

R'C

R''O + H2N R

R'C

R''N R + H2O

H+

(1) Formation of imines ( 亚胺 ) and enamine ( 烯胺 )

H2O

R' C

O

R'' + H2N R R' C R''

O

NH RH

H3O+

R' C R''

OH

HN R

carbinolamine醇胺

H3O+

R' C R''

OH2

HN R

R' C R''

HN R

-H2O

R' C R''

HN R

H2O

R' C R''

N R

Imine 亚胺Shiff base西佛碱

Catalysis: acid

Reversible reaction

可逆反应

Page 42: Carbonyl compounds

R' C

O

CH2R" + HNR

R

H3O+

R' C CHR''

OH

N R

R

HR' C CHR''

N R

R

H3O+

+ H2O

enamine

烯胺2°amine

仲胺

The pH value is crucial to imine formation. Why?

Catalyst: Acid catalyzes the dehydration.

Nu: the nucleophilicity of RNH2 can be weaken in strong acid conditions.

Product: unstable in strong acid conditions.

Page 43: Carbonyl compounds

(2) Condensation with hydroxylamine ( 羟氨 ) and hydrazine ( 肼 )

+ H2NNHC=OH2O C=NNH

NO2

NO2NO2

NO2

2,4-dinitrophenylhydrazine

2,4- 二硝基苯肼2,4-dinitrophenylhydrzone

2,4- 二硝基苯腙

C=N NH2

H2OC=O + H2NNH2

hydrazine 肼 hydrazone 腙

+ H2NOHC=OH2O C=N OH

hydroxylamine 羟胺 oxime 肟

Page 44: Carbonyl compounds

+ H2NNHCNH2C=OH2O C=NNHCNH2

O O

semicarbazide 氨基脲

semicarbazone缩氨基脲

肟、腙、缩氨基脲都是很好的结晶。有固定的熔点。在酸性水溶液中加热分解为原来的醛酮。

可用来鉴别和提纯醛、酮。如实验室常用 2 , 4- 二硝基苯肼鉴别醛、酮。

Page 45: Carbonyl compounds

H3CC

HO + H2N OH

Acetaldehyde

H3CC

HN OH

Hydroxylamine

ôÇ°·

Acetaldehyde oxime

ÒÒÈ©ë¿ÒÒÈ©

+ H2O

H2NNH

Phenylhydrazine

C6H5C

H3CN NHC6H5

Acetophenone phenylhydrazone

Ph

±½ÒÒͪ ±½ëê

CC6H5

H3CO +

Acetophenone

±½ë±½ÒÒͪ

+ H2O

O + H2NNHCNH2

O

NHNHCONH2

Cyclohexanone Cyclohexanone semicarbazone

»·¼ºÍª »·¼ºÍª Ëõ°±»ùëå

+ H2O

Semicarbazide

Page 46: Carbonyl compounds

4). Sulfur as nucleophilic atom硫为亲核原子

R

C

H

O +

HSCH2CH3

HSCH2CH3

R

C

H

SCH2CH3

SCH2CH3

H+

- H2O

ThioacetalThiol 硫醇

(1) Formation of thioacetals ( 硫缩醛和硫缩酮 )

H

C

H

O +H+

- H2OSH SH

S S

H H1,3-dithiane

1 , 3- 二噻烷

Page 47: Carbonyl compounds

(2) The addition of sodium bisulfite (NaHSO3)

产物为很好的结晶,不溶于饱和亚硫酸氢钠溶液。反应可逆,加酸可得原来的醛酮,故好可用于鉴别和提纯醛酮。

Sodium α-hydroxysulfonate

α- 羟基磺酸钠

C O

R

H (R')

+ NaHSO3 C

R

H (R')

OH

SO3Na

Page 48: Carbonyl compounds

另外,用于制备腈醇,避免了直接使用 HCN 。

PhC

HO + NaHSO3

PhC

H

OH

SO3Na

H2O NaCN

H2O

PhC

H

OH

CN

Page 49: Carbonyl compounds

Summary of the nucleophilic addition to C=O bond

1. Types of addition:

Simple addition Addition-elimination

To form C-C, C-O, C-S single bond

To form C=C, C=N double bond

2. Factors affecting the reaction rate:

(1) Steric hindrance ( 空间位阻 )

(2) Electronegative of the substituents (取代基电负性)(3) Nucleophiles (亲核试剂强度)(4) Catalyst ( 催化剂 )

Page 50: Carbonyl compounds

(1) Reactivity: Aldehydes

(2) Ability of forming hydrates:

CH3CH2CHO HCHO Cl3CCHOK: 0.7 40 500

Examples:

(3) Ability of forming cyanohydrins

CH3CHO CH3COCH2CH3 (CH3)3CCOC(CH3)3

K: > 104 38 <=1

(4) The pH is crucial to imine formation

> ketones

Page 51: Carbonyl compounds

Stereochemistry in nucleophilic addition to C=O

(1) The substrate is chiral aliphatic ketone or aldehyde

羰基加成的格拉穆( Cram )规则:

O

R

C C

L

M

S

R'MgX

2. H2O, H+

1. R'MgX

O

R

M S

LR'

OH

L

SM

R

major

R'

OH

L

SM

R

+

minor Asymmetric synthesis

不对称合成

Page 52: Carbonyl compounds

O

H

CH3

1. CH3Li

2. H3O+

H

CH3

OHH3C

+H

CH3

CH3HO

90% 10%

(2) The substrate is cyclic ketones

O

(H3C)3C

H

OH

OH

H(H3C)3C (H3C)3C+

LiAlH4 90% 10%

LiBH(sec-Bu)3 12% 88%

Page 53: Carbonyl compounds

2. Reduction and oxidation of

aldehydes and ketones

1. Reduction of aldehydes and ketones

(1) Reduction of C=O to form alcohols

R'

C

R

O R' C

R

H

OH[ H ]

[ H ]: (a) NaBH4, LiAlH4 ( in laboratory)

(b) Ni-H2, high T, P (in industry)

(c) i-PrOH / (i-PrO)3Al, Meerwein-Ponderf-Verley reaction

Page 54: Carbonyl compounds

CH3 CH

OH

CH3R C

O

R'(i-PrO)3Al

+ CH3 C

O

CH3R CH

OH

R' +

H

O

Ni-H2 H

O

H

OH

Ni-H2

H

(90%)

H

O

H2, 5% Pd/C H

O

H

O

NaBH4, or LiAlH4 H

OHH

Page 55: Carbonyl compounds

(2) Reduction of C=O to form CH2

R'

C

R

O[ H ]

R'

CH2

R

deoxygenation

[ H ]:(a) Zn (Hg), HCl, —the Clemmensen reduction.

(b) NH2NH2; KOH, heat in high boiling point solvent such as DMSO ( 二甲亚砜 ), diethylene glycol ( 一缩二乙二醇 ), etc. —the Wolff-Kishner reduction

Page 56: Carbonyl compounds

The Wolff-Kishner reduction吉日聂尔 - 沃尔夫 - 黄鸣龙反应

C NN

H

HOH

C NN

H C NN

H

H2O

OH

C NN

HH ( + -OH)C NN

H

H2O

CH H

C O H2N-NH2KOH, heat

+HOCH2CH2OCH2CH2OH

CH2 + N2 + H2O

CH( N2 +)

醛、酮和肼反应生成的腙在氢氧化钾或乙醇钠作用下分解放出氮气而生成烃 .

Page 57: Carbonyl compounds

CCH2CH3

O

CH2CH2CH3

NH2NH2 , NaOH

¡÷ (HOCH2CH2)2O

O NH2NH2, KOH, HOCH2CH2OH

heat

Page 58: Carbonyl compounds

(2) Oxidation of aldehydes and ketones

R CO

HR C

O

OH

[ O ]

[ O ] : ( 1 ) K2Cr2O7 or Na2Cr2O7 / H2SO4 ; CrO3/ H2SO4

( 2 ) KMnO4

( 3 ) Ag2O

( 4 ) Ag(NH3)2+, OH- ( Tollens reagent, 托仑试剂)

Tollens test, 银镜反应,区别醛、酮)

R C

O

H + 2 Ag(NH3)2+

+ 3 OHH2O 2Ag + R C

O

OH + 4 NH3 + H2O

Tollens test, 银镜反应

Oxidation of aldehydes

Page 59: Carbonyl compounds

the Baeyer-Villiger oxidation (拜尔 - 魏林格氧化)

Oxidation of ketonesO

HNO3HOOC CH2 COOH4

ketone ester

CO

CH3

Acetophenone

RCOOH

O

O C

O

CH3

Phenyl acetate ÒÒËá±½õ¥

RCOOH

OO

O

O

40 °C

Page 60: Carbonyl compounds

(3) The Cannizzaro reactions 康尼查罗反应

Disproportionation reaction 歧化反应

CHO COONa CH2OH2 +

NaOH, C2H5OH

~50 °CH+

COOH

HCHO + NaOHheat

HCOONa + CH3OH

Page 61: Carbonyl compounds

H C

O

H

O HOHH C

O

H+ H C

O

O + H C H

H

O

H2O

CH3OH+ OH

Mechanism:

H C

O

H + OH H C

O

H

OH

Page 62: Carbonyl compounds

Crossed Cannizzaro reaction 交叉的康尼查罗反应:

HCHO is allways the reductant.

+ HCOONaCHO + HCHONaOH CH2OH

(CH3)3CCHO + HCHONaOH

(CH3)3CCH2OH+ HCOONa

Page 63: Carbonyl compounds

Intramolecular Cannizzaro reaction分子内康尼查罗反应

Intramolecular Cannizzaro reaction分子内康尼查罗反应

Lactone内酯

δ-hydroxyl acidδ- 羟基酸

CHO

CHO

C2H5 (1) NaOH

((2) H+

COOH

CH2OH

C2H5

-H2O

O

C2H5 O

Page 64: Carbonyl compounds

Assignments

Text 1: 18-50, 51, 52, 60, 66

Text 2 (selected): 12, 14, 19

Page 65: Carbonyl compounds

Reactions of aldehydes and ketones

Summary

Nucleophilic addition to the carbon-oxygen double bond

Reactions of α-H: halogenation

Reduction and oxidation of aldehydes and ketones

Page 66: Carbonyl compounds

Name reactions

G

+ HCl + COAlCl3, CuCl

G

CHO

(1) Gatterman-Koch formylation ( 盖特曼 - 考赫甲酰化反应 )

(2) The Wittig reaction: the addition of ylide ( 叶立德 ) (18-13)

魏悌希反应

C O

R

(R')H

+ (C6H5)3P-CHR'''

R''

Phosphorus ylideÁ×Ò¶Á¢µÂ

C CR

(R')H

R''

R'''+ O P(C6H5)3

Triphenylphosphine oxideÈý±½»ùÑõì¢

Summary

Page 67: Carbonyl compounds

(3) Meerwein-Ponderf-Verley reaction

CH3 CH

OH

CH3R C

O

R'(i-PrO)3Al

+ CH3 C

O

CH3R CH

OH

R' +

(5) the Wollf-Kishner reduction 吉日聂尔 - 沃尔夫 - 黄鸣龙反应

O H2N-NH2KOH, heat

+HOCH2CH2OCH2CH2OH

CH2 + N2 + H2O

(4) the Clemmensen reduction

R

R

O

(H, Ph)

Zn (Hg), HCl. reflux

Clemmensen reduction¿ËÀ³ÃÅÉ­»¹Ô­

R

R(H, Ph)

(H, Ph) (H, Ph)

Page 68: Carbonyl compounds

(6) the Baeyer-Villiger oxidation (拜尔 - 魏林格氧化)

C

O

CH3

Acetophenone

RCOOH

O

O C

O

CH3

Phenyl acetate ÒÒËá±½õ¥

R C

O

H + 2 Ag(NH3)2+

+ 3 OHH2O 2Ag + R C

O

OH + 4 NH3 + H2O

(7) Tollens test, 银镜反应

(8) The Cannizzaro reactions 康尼查罗反应

HCHO + NaOH¡÷

HCOONa + CH3OH

Page 69: Carbonyl compounds

Assignment

• Text 1: 18-35, 37, 50, 60, 66

• Text 2: 12, 14, 19

Page 70: Carbonyl compounds

黄鸣龙 黄鸣龙 1898 年 8 月 6 日出生于江苏省扬州市,于 1979 年 7 月1 日逝世。早年留学瑞士和德国, 1924 年获柏林大学博士学位。 1952 年回国,历任中国科学理化部委员,国际《四面体》杂志名誉编辑,全国药理学会副理事长,中国化学会理事等。 黄鸣龙的一生是为科学事业艰苦奋斗的一生。他发表的论文近 80篇,综述和专论近 40 篇。主要的科研成就概述如下:( 1 )山道年一类物立体化学的研究 : 黄鸣龙最初从事植物化学研究,他博士论文题为 " 植物成分的基本化学转变 " 。稍后,开展延胡素和细辛的研究。其中,延胡索乙素现已在临床上广泛应用。

附录:

Page 71: Carbonyl compounds

1938 年,他在与 lnhoffen 研究用胆固醇改造合成雌性激素时,发现了双烯酚的移位反应。在此基础上,他随后从事山道年一类物的立体化学研究,发现了变质山道年在酸碱作用下,其相对构型可成圈地互相转变,这一发现,轰动了当时的国际有机界。各国学者根据他所解决山道年及其一类物的相对构型,相继推定了山道年一类物的绝对构型。 ( 2 )改良的凯惜纳 - 乌尔夫还原法 : 1946 年,黄鸣龙在美国哈佛大学工作时,在做凯惜纳 - 乌尔夫还原反应时,出现了意外的情况(漏气),但并未弃之不顾,而是照样研究下去,结果得到出乎意外的好产率。于是他仔细地分析原因,并经多次试验后总结如下:

Page 72: Carbonyl compounds

在将醛类或酮类的羧基还原成亚甲基时,把醛类或酮类与 NaOH 或 KOH, 85%(有时可用 50%)水合肼及双缩乙二醇或三缩乙二醇同置于圆底烧瓶中回流 3-4小时便告完成。这一方法避免了凯惜纳 - 乌尔夫还原法要使用封管和金属钠以用难于制备和价值昂贵的无水肼的缺点,产率大大提高。因此,黄鸣龙改良的凯惜纳 - 乌尔夫还原法地国际上应用广泛,并写入各国有机化学教科书中,简称黄鸣龙还原法。后来,他经常以此为例,向青年科技人员说明做实验一定要认真观察实验现象,并一再强调在反应中,出现了异常现象应尽可能地将反应结果弄明白这一实事求是、坚持真理的科学态度。

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( 3 )甾体激素的合成和有关反应的研究 : 1958 年,黄鸣龙等利用薯蓣皂为原料以七步合成了可的松,使我国的可的松合成跨进了世界先进行列。黄鸣龙对口服避孕药的结构研究和合成也作出了贡献。其中,甲地孕酮用口服避孕药不仅在我国是首创,在英国也被用作口服避孕药。

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Page 74: Carbonyl compounds

坎尼扎罗 1826 年生于意大利西西里城一个警察局长之家, 1919 年去世。 中学时的坎尼扎罗便被认为是很有才能的学生,无论文学、数学还是历史均是成绩优异。 1841 年,坎尼扎罗进入巴勒莫大学医学系学习。他以求知欲和兴趣广泛而出众。他具有杰出的才干和顽强的性格,能深刻地掌握和理解课堂讲授的内容,因而深得教授们的赏识。他不仅听医学方面的课程,还常听文学和数学方面的课程。 19岁(即 1845 年)便在那不勒斯的代表大会上作了关于辨别运动神经和感觉神经方面的报告,受到与会代表的鼓励和鞭策,促使他一方面要从生物学的角度去研究,另一方面又要从化学方面去探索。

康尼查罗( S. Cannizzaro )

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1845 年秋,坎尼扎罗前往比萨,并在著名实验家上皮利亚的实验室里当助手。在皮利亚的影响下,他深深爱上了化学这门学科。后来,他到法国巴黎,在舍夫勒实验室从事科研。 1850 年,他发表了关于氨基氰的论文,次年又发表了关于氨基氰受热后发生转化的论文。 不久,他便返回意大利的亚历山大里亚工业学院进行科学研究。有机合成的新发展,有机化学领域中一个个接踵而来的新发现,引起了他对研究苯甲醛及其特征反应的兴趣。他发现,把苯甲醛与碳酸钾一起加热时,苯甲醛特有的苦杏仁气味很快消失。产物与原来的苯甲醛完全不同,甚至气味也变得好闻了。他对反应混合物进行定量分析,先把反应混合物分成一个个组分,然后,再测定每种组分的含量。几天后,竟得几乎意料之外的结果:

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在反应过程中,碳酸钾的量没有改变,即碳酸钾只起催化剂的作用。再进一步分析得知产物中既有苯甲酸,又有苯甲醇。 1853 年,坎尼扎罗公布了他的研究成果,人们把能生成这类产物的反应称为 Cannissaro 反应。 1855 年, 39岁的坎尼扎罗在热亚大学获得教授的职位。其后,他与贝塔尼等一起完成了对苯甲醇衍生物的研究–从苄醇制苄氯,又将苄氯转变成苯乙酸。从此,他一直注意化学的基本理论问题,并写成了 " 化学哲学发展纲要 " 的论文。该论文引起了全世界科学家的重视,因为他用新的观点说明了什么是原子、分子、原子量和分子量。为此,他被特邀参加了 1860 年国际化学家代表大会并发表了独特的见解,他的思想对化学领域中的原子 - 分子学说的发展产生了决定性影响,得到与会代表的赞同,从此,坎尼扎罗名声大噪。

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坎尼扎罗毕生息于科学。由于他在化学上的杰出贡献, 1862年当选为伦敦化学学会名誉会员, 1873 年他做了纪念法拉弟的演讲并被推举为德国化学学会名誉会员。 1891 年,获得科佩尔奖章。

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Page 78: Carbonyl compounds

加特曼出生于德国的哥斯他 (Gostar) ,最初在海德尔堡学习化学,后来转到柏林学习,得博士学位,他发现了不少有机合成方法,并以他的名字而命名反应。例如: 加特曼甲酰化制备醛( 1898 ); 加特曼 - 科克甲酰化制备醛( 1897 ); 加特曼 -斯基培吡啶的合成( 1916 ); 加特曼重氮基取代作用( 1890 )。

加特曼 (Ludwing Gattermann,1860--1921 ,德国化学家 )