Question

If given this balanced equation: `2C_7H_6O + C_3H_6O -> C_17H_14O +2H_2O` Why is the acetone deprotonated and not the benzaldehyde?

Answer 1

As explained below

Explanation:

The reaction occurs according to the mechanism as shown above via the formation of carboanion (`CH_3COCH_2^-`) due to removal of proton from acetone molecule by `OH^-` ion. This ion exists as following resonance structures as enolate ion and gets stabilized thus facilitating its formation in the course of reaction. ( The resonance structures are shown below)

The deprotonation of acetone is thus favored because this stabilization of deprotonated ion from bezaldehyde is not possible.

The resonance structures of the anion obtained by deprotonation of acetone