JEE Main · 2024 · 08 Apr 2024 · Shift 2 · Aldehydes Ketones and Carboxylic Acids

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

π

bonds in the product

x

Answer: 9

Solution

Two moles of benzaldehyde (

P h C H O

) undergo a double crossed-aldol (Claisen–Schmidt) condensation with one mole of acetone under NaOH, giving dibenzylideneacetone:

P h C H = C H - C O - C H = C H P h

π

-bond count: 2 phenyl rings

\times

π

bonds each

= 6

, plus 2 alkene

C = C

bonds, plus 1 carbonyl

C = O

6 + 2 + 1 = 9

JEE Main · 2024 · 08 Apr 2024 · Shift 2 · Integer answer

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