Thermodynamically unfavored conformation of trans-4-tert-butylcyclohexyl chloride where the t-Bu group is in the axial position exerting 7-atom interactions. (en)
The trans isomer can attain antiperiplanarity only via the unfavored axial conformer; therefore, it does not eliminate. The cis isomer is already in the correct geometry in its most stable conformation; therefore, it eliminates easily. (en)