= Solution
A suitable sequence is \b[selective alpha-bromination, then <enol> O-methylation]. Use one equivalent of Br$_2$ under controlled acidic <enolization> conditions to introduce bromine at the enolizable alpha <carbon> that becomes the brominated vinyl <carbon>. The other alpha site is a constrained bridgehead and cannot form the required ordinary <enol> double bond. Then O-alkylate the <ketone> with <trimethyloxonium tetrafluoroborate> and remove the brominated alpha proton with a nonnucleophilic base such as triethylamine. Collapse of the O-methylated <carbonyl> oxonium gives \b[the alpha-bromo methyl <enol ether> E].
The methyl group belongs on <oxygen>, not on the alpha <carbon>. Simply writing methyl iodide with an unspecified <enolate> would not guarantee this outcome because competitive C-alkylation is possible. Use conditions designed for <carbonyl> O-alkylation followed by <deprotonation>, and limit bromine to avoid overbromination or damage to the <protecting group>.
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