2341
2342
2343
Some simple representative reactions
of a few functional groups.
2344
Formation of an ester:
O
CH3
C
+ CH3CH2OH
O H
carboxylic acid
alcohol
O
CH3
C
+ H2O
OCH2CH3
ester
2345
Formation of an ester:
O
CH3
C
+ CH3CH2OH
O H
carboxylic acid
alcohol
ethanoic acid ethanol
O
CH3
C
+ H2O
OCH2CH3
ester
ethyl ethanoate
2346
Oxidation of an alcohol:
H2SO4,K2Cr2O7
CH3CH2OH
alcohol
warm
2347
Oxidation of an alcohol:
H2SO4,K2Cr2O7
CH3CH2OH
alcohol
O
CH3
warm
C
H
aldehyde
2348
Oxidation of an alcohol:
H2SO4,K2Cr2O7
CH3CH2OH
alcohol
O
CH3
warm
C
H
aldehyde
further warming
O
carboxylic acid CH3 C
O H
2349
Note: In organic reactions, the side products (e.g.
Cr3+ in the preceding reaction) are often not given.
Here is the complete chemical equation:
2350
Note: In organic reactions, the side products (e.g.
Cr3+ in the preceding reaction) are often not given.
Here is the complete chemical equation:
16 H+ + 2 Cr2O72- + 3 CH3CH2OH
4 Cr3+ +3CH3CO2H
+ 11 H2O
2351
Note: In organic reactions, the side products (e.g.
Cr3+ in the preceding reaction) are often not given.
Here is the complete chemical equation:
16 H+ + 2 Cr2O72- + 3 CH3CH2OH
(orange)
4 Cr3+ +3CH3CO2H
+ 11 H2O
(green)
2352
The intermediate reaction would be:
8 H+ + Cr2O72- + 3 CH3CH2OH
(orange)
2 Cr3+ + 3 CH3CHO
+ 7 H2O
(green)
2353
Oxidation of an alcohol:
OH
CH3CHCH3
alcohol
H2SO4,K2Cr2O7
or KMnO4
(mild conditions)
O
CH3CCH3
ketone
2354
Case of a tertiary alcohol:
OH
CH3CCH3
CH3
H2SO4, K2Cr2O7
No reaction
(mild conditions)
2355
Case of a tertiary alcohol:
OH
CH3CCH3
CH3
H2SO4, K2Cr2O7
No reaction
(mild conditions)
Why is a ketone not formed?
2356
Aromatic Compounds
2357
Aromatic Compounds
Aromatic – from aroma – a number of these
compounds have strong and sometimes
pleasant odors.
2358
Aromatic Compounds
Aromatic – from aroma – a number of these
compounds have strong and sometimes
pleasant odors.
The most important compound in this family
is benzene.
2359
Benzene C6H6
This is a very important example in organic
chemistry – an example of resonance:
H
H
H C
C
H
H
H
C
C
C
C
H
C
C
H
C
H
H
C
C
H
C
H
2360
The two resonance structures are averaged
leading to the following structure:
H
C
H
H
C
C
H
C
C
C
H
H
2361
If resonance were not important for benzene, i.e.
only one of the two preceding resonance
structures were required to describe the structure
of benzene, then we might expect benzene to
have a reactivity similar to
2362
If resonance were not important for benzene, i.e.
only one of the two preceding resonance
structures were required to describe the structure
of benzene, then we might expect benzene to
have a reactivity similar to
CH2 CH CH CH CH CH2
2363
If resonance were not important for benzene, i.e.
only one of the two preceding resonance
structures were required to describe the structure
of benzene, then we might expect benzene to
have a reactivity similar to
CH2 CH CH CH CH CH2
1,3,5-hexatriene
2364
If resonance were not important for benzene, i.e.
only one of the two preceding resonance
structures were required to describe the structure
of benzene, then we might expect benzene to
have a reactivity similar to
CH2 CH CH CH CH CH2
1,3,5-hexatriene
This is not the case!
2365
If resonance were not important for benzene, i.e.
only one of the two preceding resonance
structures were required to describe the structure
of benzene, then we might expect benzene to
have a reactivity similar to
CH2 CH CH CH CH CH2
1,3,5-hexatriene
This is not the case! 1,3,5-hexatriene is fairly
reactive with a variety of reagents (e.g. HBr, Cl2,
etc. in the dark). These reagents react only slowly
with benzene.
2366
Benzene is more stable than might be
expected by examination of the individual
resonance structures.
2367
Naming benzene compounds
Cl
H
H
C
C
C
C
C
C
H
H
H
2368
Naming benzene compounds
Cl
H
H
C
C
C
C
C
C
H
H
chlorobenzene
H
2369
Br
H
H
C
C
C
C
C
C
Br
H
H
1,2-dibromobenzene
2370
Br
Br
H
H
C
C
C
C
C
C
Br
H
H
H
H
1,2-dibromobenzene
C
C
C
C
C
C
H
Br
H
1,3-dibromobenzene
2371
Br
Br
H
H
C
C
C
C
C
C
Br
H
H
H
H
1,2-dibromobenzene
C
C
C
C
C
C
H
Br
H
1,3-dibromobenzene
Br
C
H
H
1,4-dibromobenzene
H
C
C
C
C
C
Br
H
2372
Br
Br
H
H
C
C
C
C
C
C
Br
H
H
H
H
o-dibromobenzene
C
C
C
C
C
C
H
Br
H
m-dibromobenzene
Br
C
H
H
p-dibromobenzene
H
C
C
C
C
C
Br
H
2373
Br
Br
H
H
C
C
C
C
C
C
Br
H
H
H
H
o-dibromobenzene
o = ortho
m = meta
p = para
C
C
C
C
C
C
H
Br
H
m-dibromobenzene
Br
C
H
H
p-dibromobenzene
H
C
C
C
C
C
Br
H
2374
Steroids
2375
2376
2377
IUPAC name
(10R, 13R)-10,13-dimethyl-17-(6-methylheptan-2yl)-2,3,4,7,8,9,11,12,14,15,16,17-dodecahydro-1Hcyclopenta[a]phenanthren-3-ol
2378
2379
Cortisone
2380
2381
oral contraceptive
2382
2383
CH3
CH3
CH3
2384
CH3
CH3
CH3
Theobromine (replace the CH3 at the arrow by
H) is the stimulant found in
2385
CH3
CH3
CH3
Theobromine (replace the CH3 at the arrow by
H) is the stimulant found in chocolate.
2386
2387
2388
2389
Stereochemistry
2390
Stereochemistry
Stereochemistry: Deals with the 3dimensional arrangement of atoms in space
for a particular chemical structure.
2391
Stereochemistry
Stereochemistry: Deals with the 3dimensional arrangement of atoms in space
for a particular chemical structure. It also
deals with how molecules react in 3dimensions.
2392
Isomers
2393
Isomers
Two or more compounds with the same
molecular formulas but different arrangements
of the atoms in space.
2394
Isomers
Two or more compounds with the same
molecular formulas but different arrangements
of the atoms in space.
Three different types of isomerism will be
considered.
2395
Isomers
Two or more compounds with the same
molecular formulas but different arrangements
of the atoms in space.
Three different types of isomerism will be
considered.
1. Structural isomers (constitutional isomers)
2396
Isomers
Two or more compounds with the same
molecular formulas but different arrangements
of the atoms in space.
Three different types of isomerism will be
considered.
1. Structural isomers (constitutional isomers)
2. Geometric isomers
2397
Isomers
Two or more compounds with the same
molecular formulas but different arrangements
of the atoms in space.
Three different types of isomerism will be
considered.
1. Structural isomers (constitutional isomers)
2. Geometric isomers
3. Optical isomers
2398
Structural isomers
2399
Structural isomers
Structural isomers (constitutional isomers):
Compounds with the same molecular
formulas but different arrangements of the
atoms.
2400