Which of the following organic reactions represents an aldol condensation with elimination?
Answer and explanation
Correct answer: B.
- Step 1: In an aldol condensation, an enolate ion of an aldehyde or ketone attacks another carbonyl molecule, forming a -hydroxyaldehyde.
- Step 2: Upon heating, subsequent dehydration eliminates water to produce an -unsaturated carbonyl compound (crotonaldehyde: ).
- Step 3: The other reactions are Fischer esterification, dehydrohalogenation, and Friedel-Crafts alkylation.
Answer
2CH3CHO -> CH3-CH=CH-CHO + H2O.
Why not the others: Esterification produces an ester; alcoholic KOH produces an alkene from haloalkane; Friedel-Crafts alkylates benzene.
Practise more Mechanics, Waves and Electromagnetism.
Free questions with an explanation for every one, and full timed Tawjihiya Bahrain (Secondary School Certificate) mock tests.
More Mechanics, Waves and Electromagnetism questions
- A car accelerates uniformly from rest to a speed of 20 m/s in 5.0 seconds. What is the acceleration of the car?
- A horizontal net force of 50 N acts on a crate of mass 10 kg resting on a frictionless floor. What is the resulting acceleration?
- How much work is done when a constant force of 30 N moves a box by 4.0 meters along the line of action of the force?
- An object of mass 2.0 kg moves with a constant speed of 6.0 m/s. What is its kinetic energy?
- A sound wave in air has a frequency of 680 Hz. If the speed of sound in air is 340 m/s, what is its wavelength?
- Light travels from air (n1 = 1.00) into crown glass (n2 = 1.50) at an angle of incidence of 30 degrees. Find sin(theta2) for the refracted r…