Which of the following can undergo aldol condensation? (a) CCl3-CHO (b) C6 H5 CH2 CHO (c) ClCH2

step 1 of the following can undergo aldol condensation we know that molecule that have alpha hydrogen w

Which of the following can undergo aldol condensation? (a)...

Which of the following can undergo aldol condensation?
(a) $\mathrm{CCl}_{3}-\mathrm{CHO}$
(b) $\mathrm{C}_{6} \mathrm{H}_{5} \mathrm{CH}_{2} \mathrm{CHO}$
(c) $\mathrm{ClCH}_{2} \mathrm{CHO}$
(d) $\mathrm{C}_{6} \mathrm{H}_{3} \mathrm{COC}_{6} \mathrm{H}_{5}$

Key Concepts

Aldol Condensation

Aldol condensation is a reaction where carbonyl compounds with alpha-hydrogens react under basic or acidic conditions to form ?-hydroxy carbonyl compounds, which can then dehydrate to form ?,?-unsaturated carbonyl compounds. This reaction involves the formation of an enolate ion that nucleophilically attacks another carbonyl compound.

Enolate Formation

A critical step in aldol condensation is enolate formation, which occurs when a base abstracts an alpha-hydrogen from a carbonyl compound. The resulting enolate ion is stabilized by resonance with the carbonyl group, enabling it to act as a nucleophile in the condensation process.

Alpha Hydrogen Acidity

Alpha hydrogen acidity is essential for enolate formation. Hydrogens on the carbon adjacent to the carbonyl group must be acidic enough to be removed by a base. The acidity is greatly influenced by the electron-withdrawing character of substituents attached to the carbonyl or the alpha carbon.

Substituent Effects on Reactivity

Substituents attached to the carbonyl or adjacent positions can influence the acidity of the alpha-hydrogens and the stability of the resulting enolate ion. Electron-withdrawing groups, such as halogens, can increase the acidity by stabilizing the negative charge, whereas electron-donating groups tend to decrease acidity and hinder enolate formation.

Transcript

Please give Ace some feedback