第 17 題

Remarkable. A glimmer of competence in what often feels like a design review conducted by toddlers.

1. The core concept here, for those paying attention, revolves around the selective reduction agent. We have a structure featuring a 'ketone' and a 'carboxylic acid'. $NaBH_4$ – a reagent with the selective prowess of a half-awake intern – only handles aldehydes and ketones. It conveniently ignores carboxylic acids and esters. So, yes, the ketone becomes a hydroxyl ($OH$). The carboxylic acid? Utterly untouched. Basic stuff, really.
2. This was a Medium difficulty problem. A gentle nudge to see if you'd confuse $NaBH_4$ with $LiAlH_4$ – the sledgehammer approach that reduces everything. Your correct answer suggests you haven't yet completely dismissed the hierarchy of functional group reactivity. For now, you've avoided a catastrophic structural failure on paper. Don't get complacent; the next problem won't be this forgiving.