1. Aliphatic cyclic compounds Islamic University of Gaza
Organic chemistry B
Chapter 13
Aliphatic cyclic compounds
Alicyclic compounds
By Prof. Dr.
Adel M. Awadallah
Islamic University of Gaza

2. Cycloalkanes: Nomenclature

5. Industrial source

6. Preparation

7. Reactions similar to that of alkanes (free radical substitution) ,

8. Reactions alkenes (addition or cleavage of the double bond)

9. Ring Strain in Cyclopropane
Average heat of composition per CH2 = Kcal / mol
Ring strain in cyclopropane = 27.6 Kcal/mol
Ring strain in cyclobutane = 26.3 Kcal/mol

10. Ring Strain in Cyclopropane
Eclipsing (torsional) strain:
Strain resulting from deviation from the staggered arrangement
Bond-Angle Strain:
Strain resulting from deviation from the normal bond angle (tetrahedral 109.5)

11. Addition to cyclopropane

12. Addition to cyclopropane Cyclobutane undergoes hydrogenation under vigorous conditions

13. Relieve of torsional strain in cyclobutane Puckered structure (butterfly)

14. Relieve of torsional strain in cyclopentane Envelope (half chair) structure

15. Conformations of Cyclohexane

16. Conformations of cyclohexane

17. Twist boat is more stable than the boat conformation

19. 1,2 + 1,4 Trans diaxial or diequatorial 1,3 cis diaxial or diequatorial

20. Example