Question

Two moles of benzaldehyde and one mole of acetone under alkaline conditions using aqueous NaOH after heating gives $x$ as the major product. The number of $\pi$ bonds in the product $x$ is ................

Answer 1

Correct Answer: 9

The reaction involved is an aldol condensation reaction. The mechanism is as follows:

The product is formed by the reaction of two molecules of benzaldehyde (PhCHO) and one molecule of acetone (CH$_3$COCH$_3$) in the presence of alkali and heat.
The reaction involves the removal of water (H$_2$O) through dehydration, leading to the formation of a conjugated system.
The major product contains:
-3 double bonds in the benzene ring (Ph),
-2 double bonds formed during the aldol reaction,
-carbonyl (C = O) group in the product.
Total $\pi$-bonds = 9.