According to Bayer's strain theory which is highly stable?

Options

A. Cyclobutane
B. Cyclopentane
C. Cycloheptane
D. Cyclohexane

Answer

C

Explanation

Bayer's strain theory - The amount of strain is directly proportional to the angle through which a valency bond has deviated from its normal position i.e. Amount of deviation (d).
`d = (1)/(2)(109^(@)28'` - valency angle)
In cyclobutane , `d = (1)/(2) (109^(@)28' - 90^(@)) = 9^(@)44'`
In cyclopentane , `d = (1)/(2) (109^(@)28' - 108^(@)) = 0^(@)44'`
In cyclohexane, `d = (1)/(2) (109^(@)28' - 120^(@)) = -5^(@)16'`
In cycloheptane , `d = (1)/(2) (109^(@)28' - 135^(@)) = -9^(@)33'`
Cyclopentane is more stable and less reactive compared to cyclobutane, and cyclohexane and cycloheptane are free from angle of strain.Therefore quite stable.But actually Bayer's theory fails for the rings containing six or more carbone atoms.