Confirmational analysis of cyclobutane

1. Conformational
Analysis of
Cyclo butane:

2. Submitted to:
Prof. Abida Ashraf
Submitted by:
Sidra
MP-CHE-04
1st Semester
Stereochemistry CHE-533
M.Phil Organic Chemistry
Session: 2020-2022
The Women University Multan.

3. Content:
1. Cyclobutane
2. Conformations of cyclobutane
3. Inversion of Cyclobutane
4. Conformational analysis of cyclobutane
5. Representation by Ball and stick model

4. 1.Cyclobutane:
• It is 4 membered ring in two dimensions with
angle 90 degree rather than 109.5 degree.
• There would be 8 pair of eclipsed hydrogen
atoms, which account for 26.3kcal/mol and
110kJ of total strain energy. angle strain is 109.5-
90= 19 degree.

5. 2.Conformations of Cyclobutane:
Puckered Cyclobutane:
• Puckering which can
cause lowering the
torsional strain energy and
increase in the bond angle.
• Still there is lot of angle
strain but less than
cyclopropane.

6. Puckered to Butterfly form:
In 3D , the cyclobutane is flexible enough to buckle into butterfly
shape relieving torsional strain.
Puckered confirmation

7. 3.Inversion Of Cyclobutane:
Cyclobutane undergoes ring inversion, its mean one puckered
form can easily change to other form by passing through a
transition state in which the ring is planner.
The barrier to inversion in cyclobutane is 1.45kcal/mol
(5.5kJ/mol)
Puckered structure( ring flip)

9. 4.Conformational analysis of Cyclobutane:
Newman projection:
• Eclipsed Conformation:
• Staggered conformation

10. 5.Ball and stick Model:
Linear cyclobutane: Puckered Cyclobutane:
Staggered Confirmation

11. Reference:
• Chapter # 4, Organic Chemistry by Dr. Wong yau
Hsiung
• Chem.libretexts.org
• Organic conformation analysis by David A. Lightner,
Jerome E. Gurst.