Question

The correct sequence of steps involved in the mechanism of Cannizzaro's reaction is

• A. transfer of $H^-$, transfer of $H^+$ and nucleophilic attack
• B. nucleophilic attack, transfer of $H^-$ and transfer of $H^+$
• C. electrophilic attack by $OH^-$, transfer of $H^+$ and transfer of $H^-$
• D. transfer of $H^{+}$, nucleophilic attack and transfer of $H^{-}$

Answer 1

Answer: (B)

The Cannizaro reaction is as

$HCHO + HCHO \stackrel{\text { KOH (con.) }}{\longrightarrow } \underset{\text{methyl alcohol}}{CH _{3} OH}$

$+\underset{\text { acetic acid }}{ HCOOK ^{+}}$

The mechanism of Cannizaro reaction is as

Step Ist : Attack of nucleophile $OH ^{-}$ to the carbonyl carbon



Step IInd : The transfer of hydride ion from anion (I) to second molecule of aldehyde and finally rapid transfer of proton takes place.