1. Islamic University of Gaza
Organic chemistry A
Chapter 3
Alkanes
By Prof. Dr.
Adel M. Awadallah
Islamic University of Gaza

2. Alkanes and Cycloalkanes
Hydrocarbons (contain only carbon and hydrogen)
Saturated: (Contain only single bonds)
Alkanes (CnH2N + 2 )
Cycloalkanes (CnH2N )
b) Unsaturated: contain
Alkenes: double bonds (,,,CnH2N)
Alkynes: triple bonds ((CnH2N - 2)
Aromatic: benzene like compounds

3. The structure of alkanes

4. Alkyl groups

5. Nomenclature of substituted alkanes
Choose the largest continuous chain
Start numbering (lowest possible numbering)
List substituents alphabitically.
Use di, tri, tetra, penta, hexa, hepta, octa, nona, deca for identical groups
Examples

6. If there are two equally long continuous chains, choose the one with most branches

7. Conformations of Alkanes:
Conformers: Stereoisomers that are interconvertible by bond rotation

8. Potential Energy Changes in Ethane

9. Propane and Butane

10. Conformations of n-butane

11. Pentane and Hexane

12. Classes of carbon atoms and hydrogen atoms

13. Physical properties of alkanes
1) Water insoluble
2) low boiling point, which increases upon increasing the number of carbons in the alkane
3) branched alkanes have lower boiling points than the corresponding long chain alkanes

15. Industrial Sources

16. Preparation of Alkanes

17. Examples

23. Orientation of Halogenation

27. Ease of Abstraction of Hydrogen atoms

30. Transition State forHalogenation
Factors that tend to stabilize the free radical tend to stabilize the incipient free radical in the transition state

31. Non-rearrangement of free radical