Discuss the relative stabilities of various conformations of 1,3-dimethylcylohexane
Answers
The di - equatorial (most stable) arrangement is the "cis" isomer. In it, one substituent is "incline up" and one "incline down". Ring flipping gives an adaptation in which the methyl substituents are hostile to one another, however this is still trans, and this conformation is less stable since it has two axial substituents. Trans is less stable than cis isomer by 1.8 k cal / mol.
There is another isomer of 1,3-dimethylcyclohexane, the cis isomer. Cis and trans isomers are diastereoisomers, they are not diverse conformations of a similar isomer and can't be promptly interconverted by a straightforward rotational procedure. In the cis isomer, here, one methyl assemble is axial and other is equatorial, and ring flipping basically gives another proportionate compliance. Since one methyl is axial, this costs no steric strain. Thus, the cis isomer is more thermodynamically stable than the trans, which has no steric strain in the more stable conformation.
