AQA A level Chem 3.08 Aldehydes and Ketones

Aqueous NaBH₄ reduces aldehydes but does not reduce alkenes.

Explain why NaBH₄ reduces 2-methylbutanal but has no reaction with 2-methylbut-1-ene (2)

H^- ion is attracted to the first carbonyl /C^s+ (1)

H^- ion is repelled by the electron rich C=C (1)

Acrylic fibres are used as a substitute for wool. Acrylics are copolymers of acrylonitrile with other compounds.

Acrylonitrile is the common name for the following compound.

H₂C=CH-C≡N

Acrylonitrile can be formed from propene

Write an equation for the reaction for the reaction of propene with ammonia and oxygen to form acrylonitrile and one other product (1)

H₂C=CH-CH₃+ NH₃ + 3/2O₂ → CH₂=CH-C≡N + 3H₂O (1)

1

Outline how an ethanol molecule reacts with an ethanal molecule in the first step of the mechanism. Include two curly arrows to show the movement of electron pairs (2)

(2)