question_answer

The correct sequence of steps involved in the mechanism of Cannizaros reaction is

A)  nucleophilic attack, transfer of \[{{H}^{-}}\] and transfer of \[{{H}^{+}}\]

B)  transfer of \[{{H}^{-}}\], transfer of \[{{H}^{+}}\]   and nucleophilic attack

C)  transfer if \[{{H}^{+}}\] nucleophilic attack and transfer of \[{{H}^{-}}\]

D)  electrophilic attack by \[O{{H}^{-}}\], transfer of \[{{H}^{+}}\] and transfer of \[{{H}^{-}}\]

Correct Answer: A

Solution :

The Cannizaro reaction is as \[HCHO+HCHO\xrightarrow{KOH(con.)}\underset{methyl\,alcohol}{\mathop{C{{H}_{3}}OH}}\,\] \[\underset{+acetic\,acid}{\mathop{+HCOO{{K}^{+}}}}\,\] The mechanism of Cannizaro reaction is as Step 1st: Attack of nucleophile \[O{{H}^{-}}\] 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.