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A Review of “Organic Chemistry”
in First Term
Part A
Some Important Concepts and Structure
1. Different kinds of Organic Compounds.
Alkanes
Saturated Cycloalkanes
Compd. Alkyl halides
Alcohols
Alkenes
Unsaturated Alkynes
Diene
Compd.
Arenes
Reactive
intermediates
Hybrization
C atoms Geometric
structure
Alkyl
Carbocations Allylic
Radicals
Benzyl
2. Formation of Chemical bonds.
Stereoisomers
C–C σbond
Configurational
isomers
C–Hσbond
Enatiomers(R,S)
cis-trans
C=C double bonds
Diatereomers
Isomers:
C C Triple bonds Meso-isomers
(Z),(E)
Racemic mixture
Structure
Optical
Chiral
Resoactivity
Achiral
CH3CH2
nace
Optical
Mole.
CH3CH CHCH2 form
Symetric Symetric
3. Bilingual nomenclature. Unsymetric
elements
Constitutional
4. Isomers Stereoisomers Newman Projections
Fischer
Conformers
5. Aromaticity
Chair conformation
6. Organic acids and bases
7. Substitutent effects
Problem 1
The structure of Comp. A is represented
by the constitution shown:
CH3 CH CH CH CH2
Br
Cl
(a) How many of the optical isomers?
(b) Write the Fischer projections of
the optical isomers and give the IUPAC
names.
(c) Sight down the C3–C4 bond, and draw
the most stable Newman projection
formulas of the optical isomers .
(d) Identify the relationship of these optical
isomers.
Problem 2
Write a structural formula for the most
stable conformation of the each of
the following compounds:
(a) cis-Cyclohexadiol.
(b) trans-4-tert-Butyl-1-methylcyclohexane.
Give
the
stable
H
(c)
conformer.
CH
3
CH3CH2
CH3
H H
Part B. Organic Reactions
1. Radical
Reactions
a. Halogenation of alkanes.
b. α- Halogenation of alkenes.
c. Reactions of NBS.
d. Anti-Markovnikov addition:
(HBr–ROOR)
Substrates
Nucleophile
OH/H2O, EtO /EtOH,
a. Alkyl halides
2. Nucleophilic
Substitutions
C
O
CH3CO , RS , I .
N, C
C, N N N
b. Alcohols: HX, PX3, SOCl2
I
TSCl or MsCl ROTs
R X
NaOR
HX
3. Elimination
R OH
C C
H
HX
Substrates Electrophiles
HX, X2, X2+H2O,
+/H O
Alkenes
H
2
4. Electrophilic Alkynes
(HgSO4/H2SO4/H2O)
additons
B H /H O –OH -,
2
6
2
2
Conjugated 1,2-adddition
1,4-addition
dienes
cycloaddition
5. Aromatic Halogenation
Electrophilic Nitration
substitutions Sufonation
Friedel-Crafts reactions
Alkenes H2 / Pd,Ni…
Dienes H
Alkanes
6. Hydrogenations
2
Alkynes
Pd,Ni…
H2
cis-Alkenes
Lindlar-Pd
or P-2 Catalyst
Na or Li
trans-Alkenes
O Liq. NH3
RCOOH
C C
Alkenes
O3
O
Aldehydes
H2O,Zn
or
Ketones
7. Oxidations
O3
Carboxyl
Alkynes
Acids
H2O,Zn
Benzoic
+
Alkylbenzens: Na2Cr2O7/H
acid
Part C. Organic Synthesis
a. The transformation of
functional groups
Organic Synthesis
b. The change of C skeleton
c. The shift of functional
groups
Part D. Mechanism of Organic Reactions
SN1 Reactions
Rearrangea. The formation of E1 Reactions
ment
Addition of HX
a carbocation
to alkenes
Aromatic Electrophilic
substitution
b. The halonium ion: Addition of X2 to a alkene
c. Bimolecular SN2 Reactions Transition States
E2 Reactions
Reactions
Table 1 Over summary of SN1,SN2,
E1 and E2 reactions
CH3X
Methyl
RCH2X
1°
R2CHX
2°
Bimolecular reactionly
Gives
SN2
reactions
Gaves mainly SN2,
except with a hindered-strong base
[e.g.,(CH3)3CO-]
and then gives
mainly E2
Gaves mainly SN2,
with weak base
(e.g.,I-,CN -,
N3-,RCO2-)
and mainly E2
With stronger
bases(e.g.,RO -)
R3CX
3°
SN1/E1 or E2
In solvolysis give
SN1/E1,and at low
temperature SN1
is favored and gaves
mainly E2
with stronger
bases(e.g.,RO -)
Part E. Stereoselectivity of Reactions
1. Catalytic hydrogenations of alkynes:
H2 / Lindlar-Pd Syn-addition
P-2 catalyst
Li or Na / Liq. NH3: Anti-addition
2. Addition of X2 to Alkenes: Anti-addition
3. Hydroboration-Oxidation of alkenes:
Syn-addition
Syn-addition
4. Epoxidation of Alkenes:
5. SN2 Reactions: Inversion of configuration
TsCl
Retention of configuration
SN1 reaction:
6. E2 Reaction: Anti-Elimination racemization
R OH
R OTs
Part F. Regioselectivity of Reactions
1. Electrophilic addiitons of alkenes:
Markovnikov’s rule
2. Addition of HBr to a alkene in the
presence of ROOR:
Anti-Markovnikov’s rule
3. Elimination:
Zaitsev’s rule
4. Aromatic electrophilic substitution
of substituted benzenes:
Directing effect of substituents
on aromatic ring
Part G. Identification of Organic Compounds
1. Ozonolysis of alkenes and alkynes.
2. Oxidations of Alkenes by KMnO4.
3. Additions of Br2 to Alkenes.
4. Reactions of Terminal alkynes with
Ag(NH3)NO3 or Cu(NH3)Cl.
5. Reactions of conjugated dienes with
maleic anhydride.
6. Oxidations of alkylbenzenes to benzoic acid
……
1.
C N
HBr
HCN
NaCN
Br
C N
CH3
2.
CH3
CHCH2 I
Isobutyl iodide
(CH3)3C
NaOEt
Cl EtOH
NaI
Acetone
CH3
CH3
CH3
C N
(CH3)3C Cl
tert-Butyl chloride
HI
HBr
CH
CH33
CHCH
CH CH2 ROOR
ROOR
CHCH
22 IBr
CH
CH3
CH33
CHCH2 I
3.
H3C
CH3
N3
C
H C
H
Et
Et
(S)-sec-Butyl azide
H3C
H C
Et
OH
HBr
(R)-sec-Butyl alcohol
CH3
NaN 3
DMSO
C
N3
NaN3
CH3CHBrCH2CH3
H3 C
H 3C
H
C
OH
TsCl
OH
H
C
H
Et
Racemization
SN2 Reaction
OTs NaN3
acetone
Et
Et
(R)-
(R)-
N3
C
CH3
H
Et
(S)-
Problems to Chapter 8
CH2Br
P246
7.22 (d) CH3CH2CHCH2CH2CH3
1-Bromo-2-ethylpentane
2- 乙基-1-溴戊烷
3-Bromomethylhexane
7.29 (a) SN2 Rate
Br <
CH2Br
p-π conjugation
(c) also.
Electronic effect
CH3
CH3Br + CH3 ONa
CH3
CH3
Br
CH3ONa + CH3
CH3
CH3
7.30 CH3O CH3
CH3
(c)
(f)
O
O
CH3COCH3
CH3CO Na
O
+ CH3 Br
CH3COH + HO CH3
7.32
SN1:
SN2:
CH3
CH3 C
Cl >
CH3
Cl
CH2Cl
>
Steric
hindrance
CH3
CH2Cl
>
CH3 C
Cl
CH3
Cl
>
crowding
7.34
(a)
(b)
Br
CN
CH3CH2CCH2CH3 NaCN
CH3CH2CCH2CH3
CH3
CH3
CH3
CH3
CH3CHCH2CH2CH2OH
HBr
NaBr
CH3CHCH2CH2CH2Br
CH3
CH3CHCH2CH2CH2Br
(c)
SN2
OH
CH3CH2CCH3 HBr
CH3
CH3CH
H 2SO4

CCH3
CH3
CH3CH
CCH3
CH3
CH2(CH2)4CH3
7.35
Ch.P196
O
CH3C O
Br
H3C C
H
(R)-2-Bromooctane
C2H5O > HO > C6H5O > CH3CO2 > H2O
CH2(CH2)4CH3
C Br
H3C
O
CH3C O
H
C OOCCH3
H3C
SN1
CH2(CH2)4CH3
CH2(CH2)4CH3
+ CH3COO
H
CH3
H
(S)-
(R)-
Retention
Racemic-forms
C
Inversion
7.48
(a)
(b)
7.49
Br
CH
CHCH3 KOH
E1
CH2
OCH3
Br
CHCH3
CH3
H
CH3OH
heat
SN1
CH3
KOH
Br
HH
Br
H
H
H
CHCH3
CH3
Br
H
HO
CH3
CH3
E2
7.50
BrPh CH3 KOH
(
)
EtOH
Ph
H
H3C
Ph
CH3
C
C
Ph
CH3
(Z)-2,3-Diphenyl-2-butene
Br
Ph
Ph
H
7.51
(a)
CH3
H
CH3
CH3
KOH
CH3
H
Br
(b)
H3C
H3C CH3
CH3CHCBr
CH3
CH3COOH
heat
CH3C
CH3
C
CH3
Br CH3Ph
7.52
HH C H
3
(2R,3S)-2-Bromo-3-phenylbutane
Br
Ph
H3C
H
H
CH3
Ph
(Z)-2-Phenyl-2-butene
7.53(E)
7.55
CH
3
C
H
HO
CH3
H
H3C
EtONa
CH2CH3
CH3
H2SO 4
H
C
CH2CH3
H2O
SN1
H2O
CH3
CH3
C
H
HO
CH2CH3
+
C
HO
H
CH2CH3
7.58
Br
Br
C CH2CH2 C Ph
Ph
H
H
PhCH2CHBrCHBrCH2Ph
A
You should comprehend well the meaning
of the following reactions :
1.Hydroboration-Oxidation of alkenes.
2. Diels-Alder Cycloaddition Reaction.
3. Friedel-Crafts Alkylation of Arene.
4．SN2 Reaction.
5．The Williamson Synthesis of Ethers.