$α, β$ -unsaturated aldehyde is formed in the sequence?

H C H O

K O H (a q) - ------ \to

Right on! Give the BNAT exam to get a 100% scholarship for BYJUS courses

C H_{3} C H O

d i l . K O H - ------ \to

A

Δ \to

B

No worries! We‘ve got your back. Try BYJU‘S free classes today!

C C l_{3} C H O

K O H (a q) - ------ \to

No worries! We‘ve got your back. Try BYJU‘S free classes today!

C H_{3} - C (= O) - O C_{2} H_{5}

K O H (a q) - ------ \to

No worries! We‘ve got your back. Try BYJU‘S free classes today!

Open in App

Solution

The correct option is A $H C H O$ $K O H (a q) - ------ \to$
$α, β -$ unsaturated aldehyde is formed in the sequence of $H C H O K O H ⟶ (a q)$ .
In dehydration of alcohol, after removing a water molecule it produce $α, β -$ unsaturated aldehyde. Formaldehyde does not have any $α - H$ atom, so it is difficult to $(H C H O)$ undergo aldol condensation. Remember that for this reaction to occur, there has to be an aldehyde that has an alpha proton that can be removed with base. As such you can get two basic combinations
$C H_{3} C H O + C H_{3} C H O ⟶ C H_{3} - C H (O H) - C H_{2} - C H O$
$C H_{3} C H O + H C H O ⟶ H O - C H_{2} - C H_{2} - C H O$
These products are not particularly stable under the reaction conditions and tend to eliminates water so that the $α, β -$ unsaturated product are obtained.
$C H_{3} - C H (O H) - C H_{2} - C H O (B a s e c a t a) ⟶ C H_{3} - C H = C H - C H O$
$H - O - C H_{2} - C H_{2} - C H O (B a s e c a t a) ⟶ C H_{2} = C H - C H O$

Suggest Corrections