Which of the following best represents the enol tautomer of ${\mathrm{CH}}_3{\mathrm{CO}}_2\mathrm{CH}{3}_2$ (acetone)?

• A. ${\mathrm{CH}}_{3}C\left(\mathrm{OH}\right)=\mathrm{CH}{2}_{\mathrm{}}$
• B. ${\mathrm{CH}}_3\mathrm{CH}=\mathrm{COH}$
• C. ${\mathrm{CH}}_2=C\left(\mathrm{OH}\right){\mathrm{CH}}_3$
• D. ${\mathrm{CH}}_3\mathrm{COCH}{3}_2$

Answer: (C)

Verified step by step guidance

1. Identify the structure of acetone, which is CH\_3-CO-CH\_3, a ketone with a carbonyl group (C=O) flanked by two methyl groups.
2. Recall that enol tautomers involve the migration of a proton from an alpha carbon (adjacent to the carbonyl) to the oxygen of the carbonyl, converting the C=O into a C-OH and forming a C=C double bond between the alpha carbon and the carbonyl carbon.
3. Locate the alpha carbons in acetone, which are the two methyl groups adjacent to the carbonyl carbon, and consider the proton shift from one of these methyl groups to the oxygen atom of the carbonyl.
4. Write the enol form by replacing the C=O with a C-OH group and introducing a C=C double bond between the alpha carbon and the carbonyl carbon, resulting in the structure CH\_2= C(OH)-CH\_3.
5. Compare the given options to this structure and select the one that matches the enol tautomer of acetone, which has the hydroxyl group attached to the former carbonyl carbon and a double bond between that carbon and the adjacent alpha carbon.