Which of the following represents the enol form of ${\mathrm{CH}}_3\mathrm{COCH}{3}_{}$ (acetone)?

• A. ${\mathrm{CH}}_3\mathrm{COHCH}{2}_{}$
• B. ${\mathrm{CH}}_3\mathrm{COH}=\mathrm{CH}{2}_{}$
• C. ${\mathrm{CH}}_3\mathrm{COCH}{3}_{}$
• D. ${\mathrm{CH}}_{3}C=\mathrm{CH}{2}_{}+H{2}_{}O$

Answer: (B)

Verified step by step guidance

1. Identify the keto form of acetone, which is given as \(\mathrm{CH_3COCH_3}\). This structure has a carbonyl group (C=O) at the central carbon.
2. Understand that the enol form involves the migration of a proton (H) from an alpha carbon (adjacent to the carbonyl) to the oxygen, converting the C=O into an OH group and forming a C=C double bond between the alpha carbon and the carbonyl carbon.
3. Draw the enol form by replacing the carbonyl oxygen double bond with a hydroxyl group (OH) and creating a double bond between the central carbon and one of the methyl carbons, resulting in \(\mathrm{CH_3C(OH)=CH_2}\).
4. Recognize that the enol form is a tautomer of the keto form, and the two structures differ in the position of the double bond and the hydrogen atom.
5. Compare the given options to the enol structure \(\mathrm{CH_3C(OH)=CH_2}\) to identify the correct representation of the enol form of acetone.