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CAIE A Level Chemistry 9701

Organic synthesis questions

Exam-style questions on Organic synthesis, ordered from foundation to challenge. Pick one, write your answer the way you would in the exam, and it comes back marked against the mark scheme, point by point.

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Written by Markquill to follow the Cambridge International syllabus. Markquill is independent and is not affiliated with or endorsed by Cambridge International.

  1. Explain4 marksStandardA compound isolated from a natural oil is found to contain a benzene ring, a carboxylic acid group and an alkene group. A student proposes the following two-step route to convert this compound into a saturated alcohol…
  2. Describe5 marksStandardA molecule of methyl 3-methylbut-2-enoate has the structure CH3-C(CH3)=CH-COOCH3 It contains both an alkene group and an ester group. Describe the reactions of this molecule with each of the following reagents, stating…
  3. Explain4 marksStandardA student plans to prepare 2-hydroxybutanenitrile, CH3CH2CH(OH)CN, starting from propanal, CH3CH2CHO, and hydrogen cyanide. The route is: Step 1: propanal is warmed with an aqueous solution of sodium cyanide and a…
  4. Explain4 marksStandardA student claims that propene can be converted to 3-hydroxybutanal (CH3CH(OH)CH2CHO) in two steps. Step 1: Propene is treated with steam and phosphoric acid at 300°C and 60 atm, forming compound X. Step 2: Compound X…
  5. Compare5 marksStandardA student plans to prepare the compound methyl 3-oxobutanoate, CH3COCH2CO2CH3, which contains both a ketone and an ester group. Two routes are proposed. Route 1: CH3COCH3 is treated with Cl2 in the presence of NaOH to…
  6. Describe5 marksStandardA student plans to prepare a diamide from a diacid. The diacid has the formula HOOC-CH2-CH2-CH2-COOH and the amine is CH3NH2. The student proposes the following two-step route: Step 1: the diacid is warmed with an…
  7. Describe5 marksStandardAspirin is prepared by reacting 2-hydroxybenzoic acid (salicylic acid) with ethanoic anhydride. The structure of aspirin contains a benzene ring, a carboxylic acid group, and an ester group. Describe how you would…
  8. Explain4 marksStandardA student plans to prepare cyclohexanol from cyclohexene. The proposed route is: Step 1: cyclohexene is treated with steam in the presence of an acid catalyst. Step 2: the product of Step 1 is purified by distillation…
  9. Compare5 marksStandardA student proposes to prepare 2-hydroxybutanoic acid, CH3CH2CH(OH)COOH, from 1-chloropropane, CH3CH2CH2Cl, using the following three-step route. Step 1: 1-chloropropane is heated with aqueous sodium hydroxide to form…
  10. Describe5 marksStandardAspirin can be prepared from methyl salicylate, the compound responsible for the smell of wintergreen. The synthesis is carried out in two steps. Step 1: Methyl salicylate is refluxed with an excess of aqueous sodium…
  11. Compare5 marksStandard2-Hydroxypropanoic acid (lactic acid) contains both a carboxylic acid and a secondary alcohol functional group. Two different synthetic routes to this compound are described below. Route 1 Step 1: Ethanal is treated…
  12. Describe5 marksStandardA student plans to prepare the ester isopropyl ethanoate by refluxing propan-2-ol with ethanoic acid in the presence of concentrated sulfuric acid. Describe the type of reaction taking place and the reagent used to…
  13. Explain4 marksStandardA student wants to convert 4-nitrotoluene into 4-aminobenzoic acid using the following two-step synthetic route. Step 1: 4-nitrotoluene + hot alkaline KMnO4 → compound A Step 2: compound A + Sn / concentrated HCl →…
  14. Explain4 marksStandardA student plans to convert cyclohexene into cyclohexanol. The student reacts cyclohexene with steam in the presence of an acid catalyst. Explain, in terms of the functional groups present, why the product of this…
  15. Suggest4 marksStandardPhenylmethanamine, C6H5CH2NH2, is a primary amine that can be prepared from benzene. Suggest a three-step synthesis of phenylmethanamine from benzene, naming the reagent(s) and conditions for each step and stating the…
  16. Describe5 marksStandardCompound X has the formula CH3CH2COOCH2CH=CH2. It contains an ester group and an alkene group. Describe two reactions of X, one involving the ester group and one involving the alkene group. For each reaction, state the…
  17. Compare5 marksStandard2-Methoxybenzoic acid can be prepared by two synthetic routes. Route A: Step 1: 2-hydroxybenzoic acid is reacted with methyl iodide in the presence of aqueous sodium hydroxide. Step 2: The product from step 1 is…
  18. Describe5 marksStandardA student plans to prepare the ester propyl propanoate by refluxing propan-1-ol with propanoic acid and a few drops of concentrated sulfuric acid. Instead of propan-1-ol, the student uses propan-2-ol, a secondary…
  19. Explain4 marksStandardThe following synthetic route is used to convert 1-bromobutane (CH3CH2CH2CH2Br) into pentanoic acid (CH3CH2CH2CH2COOH). Step 1: 1-bromobutane is treated with aqueous potassium cyanide in ethanol at reflux to form…
  20. Describe5 marksStandardA student plans to prepare a symmetrical diamide, (CH3)2C(CONH2)2, from 2,2-dimethylpropanedioic acid, (CH3)2C(COOH)2. The student proposes the following two-step route. Step 1: 2,2-dimethylpropanedioic acid is warmed…
  21. Compare5 marksStandardA student prepares compound X, CH3COCH2CH2CO2CH3, a keto-ester. The student treats X with aqueous sodium hydroxide, then with dilute hydrochloric acid, and obtains compound Y. In a separate experiment, the student…
  22. Explain4 marksStandardA naturally occurring oil is extracted from the seeds of a tropical plant. A sample of the oil is known to contain a single ester molecule. The molecule has one ester group, one carbon-carbon double bond and one…
  23. Compare5 marksStandardA colourless liquid, X, is known to contain carbon, hydrogen and oxygen only. A student carries out three tests on separate samples of X. Test 1: Sodium hydrogencarbonate is added. Effervescence is observed. Test 2: A…
  24. Explain6 marksChallengeA student plans to prepare cyclohexanol from cyclohexene. The proposed route is: Step 1: cyclohexene is shaken with cold, concentrated sulfuric acid. Step 2: the mixture is then warmed with water. Explain why Step 1 is…
  25. Suggest6 marksChallengeA student plans to prepare propylamine, CH3CH2CH2NH2, starting from 1-chloropropane, CH3CH2CH2Cl. The student suggests heating 1-chloropropane with an excess of ammonia dissolved in ethanol in a sealed tube. Suggest…
  26. Explain7 marksChallengeA student plans to prepare 2-hydroxybutanenitrile, CH3CH2CH(OH)CN, starting from propanal, CH3CH2CHO. The proposed route is: propanal is treated with an excess of hydrogen cyanide, HCN, and a small amount of potassium…
  27. Describe6 marksChallengeMethyl salicylate, HOC6H4COOCH3, is hydrolysed with aqueous sodium hydroxide to form sodium salicylate, NaOOC-C6H4-OH. The sodium salicylate is then acidified to form salicylic acid, HOOC-C6H4-OH. Salicylic acid is…
  28. Compare5 marksChallengeA student plans two separate preparations from the keto-ester ethyl 3-oxobutanoate, which contains both an ester group and a ketone group. Route 1: the keto-ester is heated under reflux with an excess of aqueous sodium…
  29. Explain5 marksChallengeA student plans to prepare compound X, whose structure contains a benzene ring with both a carboxyl group and an amide group. The proposed route is: Step 1: methylbenzene is refluxed with acidified potassium…
  30. Suggest5 marksChallengeA student plans to prepare propan-1-amine, CH3CH2CH2NH2, starting from 1-bromopropane, CH3CH2CH2Br. Suggest a suitable preparation, naming the reagent and conditions, and explain why a mixture of amines is obtained and…
  31. Describe7 marksChallengeDescribe a synthetic route from methylbenzene to 3-nitrobenzoic acid. For each step of your route, identify the type of reaction, suggest suitable reagents and conditions, and state any possible by-products.
  32. Suggest7 marksChallengeA student plans to prepare 2-hydroxy-3-methylbutanoic acid, CH3CH(CH3)CH(OH)COOH, starting from 2-methylpropanal, (CH3)2CHCHO. (a) The first step is to convert the aldehyde into a cyanohydrin using HCN. Suggest a…
  33. Compare7 marksChallengeAn unknown organic compound, C3H6O2, is treated with separate samples of sodium carbonate, Tollens' reagent, and bromine water. The observations are recorded. With sodium carbonate, effervescence is seen. With Tollens'…
  34. Suggest5 marksChallengePropanone reacts with phenylmagnesium bromide, C6H5MgBr, followed by aqueous acid, to give 2-phenylpropan-2-ol. A student proposes to prepare this alcohol by adding propanone to an excess of phenylmagnesium bromide…