4. Consider cis-trans isomers of cyclohexanes. i) Draw both chair conformations for cis-1-bromo-2-ethylcyclohexane. Considering only 1,3-diaxial interactions, calculate the energies of each conformer. ii) Draw both chair conformations for trans-1-bromo-2-ethylcyclohexane. Considering only 1,3-diaxial interactions, calculate the energies of each conformer. iii) Which isomer will undergo E2 elimination reaction the fastest? Briefly state why