Write the structures of all the alkenes that can be formed by dehydrohalogenation of each of the following alkyl halides. Apply the Zaitsev rule to predict the alkene formed in greatest amount in each case.
(a) 2-Bromo-2,3-dimethylbutane (d) 2-Bromo-3-methylbutane
(b) tert-Butyl chloride (e) 1-Bromo-3-methylbutane
(c) 3-Bromo-3-ethylpentane (f) 1-Iodo-1-methylcyclohexane