BSc Chemistry SEM V 2018 19 2018-19 Chemistry Organic Chemistry Question Paper - Mumbai University | munotes

Questions asked in this paper

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1. Q3 Use of non-programmable calculators or log tables is allowed
2. Q1 Answer any three:
   • A) Explain the Benzilic rearrangement reaction with mechanism and two applications. 05
   • B) a) Discuss the stereochemistry of Beckmann rearrangement. 03
   • b) Write any two applications of the Wittig reaction. 02
   • C) a) Explain the term ‘nucleophilicity’. How does it differ from basicity 03
   • b) What is Es reaction? Give its mechanism. 02
   • D) Explain the following reactions with one example and give the relevant mechanism 05
   • a) Esterification
   • b) Pyrolysis of acetates
   • E) An active methylene compound adds to the double bond of an carbonyl 05 compound in the presence of a basic catalyst. Name the reaction and give its mechanism
   • F) a) Complete the following reaction. Write the mechanism involved. 03
   • b) What is NGP reaction? What is the importance of the neighbouring group?
3. Q2 Answer any three:
   • A) Explain the term molecular chirality with suitable examples. What are elements of symmetry? 05 Explain rotation - reflection axis
   • B) Discuss the stereochemical features of a biphenyl system with suitable examples. 05
   • C) What are the different types of strains in cycloalkanes? Explain them. 05
   • D) Discuss the following: 05
   • a) isomerism in 1,3-Dimethyl cyclohexane
   • b) atoms and faces
   • E) Explain why bromination of olefins is a stereospecific process. 05
   • F) Discuss the stereochemistry of SN? reaction at a chiral carbon with a suitable example. 05 Answer any three of the following:
   • A) Explain Simmon-Smith reaction. Discuss its mechanism and applications. 05
   • B) How is Phenyl lithium prepared? What is the action of following on lithium? 05
   • C) Give the preparation of ethyl magnesium bromide. How are the following compounds prepared 05
   • D) Complete the following reactions: 05
   • i) He
   • E) a) Explain methane rearrangement with mechanism. 03
   • b) With a neat and labelled Jablonski diagram and explain the process of inter system 02
   • F) a) Explain Norrish type II reaction using a suitable example. 02
   • b) Explain the photoreduction of Benzophenone to Benzpinacol. 03
4. Q4 Answer any three:
   • A) Explain the following with suitable examples. 05
   • B) a) Explain in brief using suitable examples: 03
   • b) Write the multicomponent synthesis of Mannich base. 02
   • C) What are the various types of catalysts used in green chemistry? What are their advantages? 05
   • D) a) Give any three principles of green chemistry. 03
   • b) Define: 1) Synthetic equivalent 02
   • E) a) Explain the use of functional group interconversion (FGI) in retro analysis. 03
   • b) Calculate the percentage atom economy for the following reaction: 02
   • F) a) Write the synthesis of Paracetamol. 03
   • b) Give the advantages of ultra sound in organic synthesis. 02
5. Q5 State whether the following statements are True or False: 4 marks
   • a) The Pinacol-pinacolone rearrangement reaction involves a 1,4 shift of the alkyl group
   • b) Pinacols are highly substituted diols
   • c) Urea reacts with halogens in the presence of a strong base to form hydrazine
   • A), Choose the correct option and rewrite the statement: 04
   • p) Base hydrolysis of oil is called
   • q) Acidity is the extent to which a compound accepts
   • r) formation of a carbene from chloroform in the presence of a base is an example of
   • s) The Wittig reaction leads to the formation of substituted 2 State whether the following molecules are chiral or achiral. 04
   • a) b) cl
   • B) State whether the following are true or false: 04
   • p) Achiral molecule is dissymmetric
   • q) All stereoselective reactions are enantioselective
   • r) Biphenyl-2,2'-disulphonic acid can be resolved
   • s) Boat form of cyclohexanol has greater energy than the chair form
   • C) Write the structure of the following compounds: 04
   • c) 2-penta diene
   • C) Write the IUPAC name of the following structures: 04
   • D) Complete the reaction: 03
   • D) Match the columns appropriately: 03
   • p) Choline chloride and glycerol 1) transfer Catalysts
6. Q5 Green reagents

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