Multistep Synthesis with Ethanol Solvents or 1,2-diol

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You have the right idea in your attempts at this problem. Exploiting the greater reactivity of aldehydes over ketones towards nucleophilic attack (make sure you understand why) allows the selective formation of the acetal of the aldehyde. However, rather than use ethanol, I would opt for a 1,2-diol. That way, you can more carefully control the number of equivalents used (ie 1 equivalent) and there is no risk of forming the hemiacetal or acetal of the ketone.

So, in the first step, I would use ethan-1,2-diol, in the presence of acid catlyst. Remember this is an equilibrium reaction, so you need to continuously remove water from the system in order to drive the reaction to completion. This gives 'A' ...