JEE Main 2024 · Chemistry · Carbonyl Compounds, Carboxylic Acids and Amines · hard
Acetaldehyde is treated with excess formaldehyde in the presence of concentrated NaOH. The organic products formed are
Single correct option
Acetaldehyde is treated with excess formaldehyde in the presence of concentrated NaOH. The organic products formed are
A.C(CH2OH)4 and HCOONa
B.CH3CH(OH)CH2CHO only
C.(HOCH2)3CCHO and CH3OH
D.HOCH2CH2CH2OH and HCOONa
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Answer:(A) C(CH2OH)4 and HCOONa
Acetaldehyde has three α-hydrogens and formaldehyde has none, so three successive crossed aldol additions with HCHO give (HOCH2)3C−CHO. This aldehyde has no α-H and, in the presence of excess HCHO and strong base, undergoes crossed Cannizzaro reaction: HCHO is oxidised to formate and the hindered aldehyde is reduced to CH2OH. The product is pentaerythritol, C(CH2OH)4, with sodium formate.