Home › JEE Advanced › Chemistry › Aldehydes, Ketones and Carboxylic Acids › For α,β-unsaturated ketones (enones), 1,4-additi…
For α,β-unsaturated ketones (enones), 1,4-addition (Michael) competes with 1,2-addition. Soft nucleophiles prefer:
ANeither
B1,2
CBoth equally
D1,4 (Michael acceptor)
Answer & Solution
Correct answer: D. 1,4 (Michael acceptor)
HSAB principle: soft nucleophiles (e.g., R₂CuLi, RS⁻) attack soft C=C of enone (1,4 addition / Michael). Hard nucleophiles (e.g., RMgX, RLi) attack hard C=O (1,2 addition). Synthetic strategy.
Related questions
Against ketones, aldehydes in nucleophilic addition are:Aldehydes and ketones take part in addition that is:Solubility of aldehydes falls as the alkyl chain grows:Methanal, ethanal and propanone mix with water in:Aldehydes boil lower than alcohols of like mass because they lack:Aldehydes boil higher than hydrocarbons of like mass because of:At room temperature methanal exists as a:The carbonyl carbon behaves as a centre that is: