BSc Chemistry SEM V ATKT CHEMISTRY PAPER III ORGANIC CHEMISTRY Question Paper - Mumbai University | munotes

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1. Q3 Use of non-programmable calculators or log tables is allowed
2. Q1 Answer any three:
   • A) a) Ethyl bromide reacts with KOH alcohol. Write the reaction and give the mechanism. 03
   • b) What are the factors affecting the E; mechanism. 02
   • B) What are electrophiles? State whether the following are electrophiles or nucleophiles. 05
   • C) Explain the Pinacol-pinacolone rearrangement reaction with one example and mechanism. 05
   • D) Syn methyl! phenyl ketoxime reacts with conc. sulphuric acid. Identify the reaction. Write the 05 product and mechanism
   • E) Convert benzamide to aniline in the presence of halogens and a strong base. Name the reaction 05 and give its mechanism
   • a) How is benzoic acid converted to an ester? Write the mechanism. 03
   • b) State and explain the Saytzev’s rule. 02
3. Q2 Answer any three:
   • A) Discuss molecular chirality in substituted cummulenes with suitable examples. 05
   • B) What are elements of symmetry? Explain mirror plane and inversion centre with proper 05
   • C) Discuss the conformation of cyclohexane, Label them as cis or trans and point out 05 the most stable and least stable conformer
   • D) Discuss angle strain and torsional strain in cycloalkanes. 05
   • E) Give an example of a SN! reaction at a chiral carbon and explain the stereochemistry involved. 05
   • F) Discuss the stereospecificity of the dehydrohalogenation of 1-bromo-1, 2-diphenyl propane. 05 Answer any three:
   • A) a) Give the preparation of 03
   • i). n-Butyl lithium
   • b) What is the action of Lithium dimethyl cuprate on: 02
   • i) ii)
   • B) Explain Reformatsky reaction. Discuss its mechanism and application. 05
   • C) a) What are Grignard reagents? Give the preparation of Methyl magnesium iodide. 03
   • D) Complete the following reactions: 05
   • e) + 1 on
   • E) a) With a neat and labelled Jablonski diagram, explain the phenomenon of fluorescence 03
   • b) What is intersystem crossing? Is it an allowed or forbidden transition? Why? 02
   • F) a) Explain Norrish Type I reaction of Acetone at 03
   • b) What is Photosensitisation? Explain with an example. 02
4. Q4 Answer any three:
   • A) Explain the following with suitable examples. 05
   • B) a) Define: 03
   • b) Write the retro synthesis of Limonene. 02
   • C) What are linear synthesis and multi component synthesis? Give the Hantsch synthesis of 05
   • D) a) Calculate the percentage atom economy for the following reaction: 03
   • b) Define E-factor and Atom economy
   • E) Explain the use of the following: 05
5. Q1 Supercritical CO2 as solvent Dimethyl Carbonate as methylating agent
   • F) Explain the advantages of microwave assisted reactions in organic synthesis with suitable 05
   • A). State whether the following statements are True or False: 04
   • a) Diethyl malonate is a reactive methylene compound Acrolein is an - unsaturated aldehyde
   • d) Benzilic acid rearrangement yields benzoic acid as one of the products
   • A) Choose the correct option and rewrite the statement: 04
   • p) The mechanism takes place in step
   • q) Basicity is the extent to which a base accepts a ‘
   • s) Favorski rearrangement reaction mechanism proceeds via the formation of a as an intermediate State whether the following molecules are chiral or achiral. 04
   • B) State whether the following are true or false: 04
   • p) reactions are not stereospecific
   • q) is more stable than cyclopropane
   • r) molecules should contain one or more asymmetric carbon atoms containing odd number of double bonds exhibit geometrical isomerism Write the IUPAC name of the following structures: 04
   • C) Write the structure of the following compounds: 04
   • p) Hepta-2,3,4-triene
   • D) Complete the reaction: 03
   • D) Match the columns appropriately:

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