How many of the following compounds can undergo keto-enol tautomerism? CH3CHO, C6H5CHO, C6H5COCH3, (CH3)3C-CO-C(CH3)3, CH3COCH(CH3)2, HCHO

JEE Main levelSingle correct optionDifficulty 2 of 3g2186

How many of the following compounds can undergo keto-enol tautomerism? $CH X_{3} CHO$ , $C X_{6} H X_{5} CHO$ , $C X_{6} H X_{5} COCH X_{3}$ , $(CH X_{3}) X_{3} C - CO - C (CH X_{3}) X_{3}$ , $CH X_{3} COCH (CH X_{3}) X_{2}$ , $HCHO$

Enolisation needs an alpha hydrogen.

CH X_{3} CHO

(yes),

C X_{6} H X_{5} CHO

(no),

C X_{6} H X_{5} COCH X_{3}

(yes, the methyl hydrogens),

(CH X_{3}) X_{3} C - CO - C (CH X_{3}) X_{3}

(no, the alpha carbons are quaternary),

CH X_{3} COCH (CH X_{3}) X_{2}

(yes),

HCHO

(no). Count

= 3