1. Lesson 65 - Organic Chemistry I

2. synthetic fibres plastics artificial sweeteners drugs coal, petroleum

3. Organic Chemistry originally meant chemistry of “organisms”
now means chemistry of
C - containing compounds
(but not CO2, H2CO3, etc.)

4. organic compounds once thought to have a “life force” until 1828...
Organic Chemistry
organic compounds once thought to have a “life force” until
NH4OCN ® H2N - C - NH2 = O D
ammonium
cyanate
urea
(inorganic)
(organic)

5. What’s so special about C?
Organic Chemistry
What’s so special about C?

6. Organic Chemistry What’s so special about C? - it bonds to itself
® long chains
® ring structures
- it bonds to H, N, O, S, halogens, etc.

7. C : living things as Si : rocks
Organic Chemistry
C : living things as
Si : rocks

8. » 107 compounds known so far » 90% of them are organic
Organic Compounds
» 107 compounds known so far
» 90% of them are organic

9. most other organic compounds are derivatives of hydrocarbons
made only of C, H
most other organic compounds are derivatives of hydrocarbons

10. Hydrocarbons
Methane,
CH4

11. (each C is bound to 4 other atoms)
Alkanes
general formula CnH2n+2
alkanes are saturated
(each C is bound to 4 other atoms)

12. Alkanes: Saturated Hydrocarbons
C = C
+ H2(g) ®
H - C - C - H(g) H
H(g) H H
Unsaturated
Saturated
(Ethane)

13. saturated vs. unsaturated fatty acids=O OH =O OH

14. Alkanes: Saturated Hydrocarbons
CH4 methane natural gas
C2H6 ethane making ethylene
C3H8 propane heating, barbecues
C4H10 butane lighter fluid
C5H12 pentane solvent
C6H14 hexane part of gasoline
then heptane, octane, nonane, decane

15. Isomers
methane
1 isomer
ethane
1 isomer
propane
1 isomer

16. Isomers
normal butane
(n-butane)
isobutane

17. Drawing Structures n-butane CH3CH2CH2CH3 isobutane CH3CHCH3CH3 single
bonds
isobutane
CH3CHCH3CH3

18. Draw all the isomers of pentane (C5H12)
Drawing Structures
Draw all the isomers of pentane (C5H12)
1. CH3 - CH2 - CH2 - CH2 - CH3
(n-pentane)

19. 1. CH3 - CH2 - CH2 - CH2 - CH3
(n-pentane)
CH3
2. CH3 - CH - CH2 - CH3
(isopentane)

20. CH3
2. CH3 - CH - CH2 - CH3
(isopentane)
CH3
3. CH3 - C - CH3
CH3
(neopentane)

21. Equivalent Structures

22. a systematic naming system e.g.
Nomenclature
a systematic naming system
e.g.
CH3 - CH2 - CH - CH2 - CH3
CH2
CH3

23. Nomenclature CH3 6 carbons CH2 CH3 - CH2 - CH - CH2 - CH3
1. Find the longest continuous chain
of carbon atoms; this is a hexane
2. Alkane groups as substituents are
named as follows:

24. - CH3 methyl - CH2CH3 ethyl - CH2CH2CH3 propyl CH3CHCH3 isopropyl
Alkyl Groups
- CH3 methyl
- CH2CH3 ethyl
- CH2CH2CH3 propyl
CH3CHCH3 isopropyl

25. - CH2CH2CH2CH3 butyl
CH3CHCH2CH3 sec-butyl
- CH2 - C - CH3 iso-butyl
- C - CH3 tert-butyl H
CH3
CH3
CH3

26. 3. Number the long chain so that the 6 5
CH2
CH2 4
CH3 - CH2 - CH - CH2 - CH3 3 2 1
ethyl
hexane
3. Number the long chain so that the
substituents are at the lowest numbers
3-ethylhexane

27. other examples 2- methyl pentane 2,4- dimethyl pentane1 3 5
2,4-
dimethyl
pentane 1 2 3 4 5
2,2,4-trimethylpentane
(isooctane, octane rating = 100) 2 4 1 3 5

28. other examples
4-ethyl-3,5-dimethylnonane 4 1 9

29. other examples
4-tert-butylheptane

30. Cycloalkanes =
cyclopropane

31. Cycloalkanes
cyclobutane
cyclopentane
cyclohexane