BSc Chemistry SEM V 2016 17 2016-17 Organic Chemistry Question Paper - Mumbai University | munotes

Questions asked in this paper

• (2) Figures to the right indicate full marks

1. Q1 Answer any three of the following
   • (A) What is neighbouring group participation effect? Explain its 5 mechanism. Illustrate with a suitable example
   • (B) (a) Give the mechanism involved in Favorskii rearrangement. 3
   • (b) Explain the term nucleophilicity with relevant examples. 2
   • (C) (a) following reactions. 3
   • (b) Explain Hofmann elimination with an example. 2
   • (D) Complete the following reaction, name the reaction involved and 5 give a suitable mechanism
   • (a) What is El reaction? Explain its mechanism. 3
   • (b) Discuss the stereochemistry of Beckmann rearrangement. 2
   • (F) (a) Suggest a ‘suitable mechanism involved in the following 3
   • (b) What is an acyl nucleophilic substitution? Give an example. 2
2. Q2 Answer any three of the following
   • (A) Complete the following reaction. Explain its $,,2 mechanism and 5
   • (B) Draw all the four important conformations of cyclohexane. Which 5 of these is the most stable conformation? Why?
   • (C) Define the following and explain with suitable examples of organic 5
   • (a) Centre of symmetry
   • (b) Alternating axis of symmetry
   • (D) Explain the stereochemistry of catatylic hydrogenation of cis and 5 trans isomers of 2,3-diphenyl-2-butene :
   • (E) Explain the mechanism of syn-hydroxylation of olefins using 5 potassium permanganate. Also explain the stereochemistry of syn hydroxylation of trans-2-butenedioic acid
   • (F) Explain molecular chirality of substituted allenes wtih suitable 5
3. Q3 Answer any three of the following :—
   • (A) Give the preparation 5
   • (ii) Phenylithium What is the action of CH,CN on phenyl lithium?
   • (B) (a) How are the following compounds prepared using 3
   • (i) 1-propanol
   • (ii) 2-hexanol
   • (b) Give the reaction of methyl lithium with an epoxide 2
   • (C) How is zinc iodide prepared? Discuss mechanism and 5 applications of Simmons-Smith reaction
   • (D) Complete the following reactions 5
   • (E) With the help of a neat and labelled Jablonski diagram, explain the 5 phenomenon of fluorescence. Is it an allowed or a
   • (F) Explain photoreduction of benzophenone to benzpinacol in a 5
4. Q4 Answer any three of the following
   • (A) Explain polymer supported polypeptide synthesis 5
   • (B) Explain the use of the following in Green Chemistry 5
   • (a) Supercritical CO,
   • (C) Explain the following terms in retrosynthesis 5
   • (D) (a) Define (i) Target molecule 3
   • (ii) E-factor
   • (b) Explain atom economy with suitable example. - 2
   • (E) (a) Explain the use of green reagents in organic synthesis with 3
   • (b) Give the green synthesis of adipic acid. 2
   • (F) Explain the following 5
   • (a) Enzymatic catalysts
   • (b) Any three important principles of green chemistry
5. Q5 (A) Choose the right answer from the alternatives given below each and rewrite the completed statements Dehydrohalogenation of bromoethane takes place through 4 marks
   • (b) Cope elimination is observed in
   • (c) In the reaction R-I + OH >
   • (d) The alkaline hydrolysis of an ester is a process
   • (A) State if the following are true or false
   • (q) Basicity affects the rate of reaction
   • (r) state cannot be isolated
   • (s) E, elimination preferably takes place from the syn-periplanar
   • (B) State whether the following are true or false
   • (a) In epoxidation of olefins, a trans-substrate gives a cis-oxirane
   • (b) In syn-hydroxylation of olefins using potassium permanganate,
   • (c) When treated with thionyl chloride, an R-alcohol gives as S
   • (d) When treated with aq.KOH, an R-alkylhalide (secondary). gives
   • (B) State whether the following molecules are chiral or achiral 4
   • (C) Give names of the following 4
   • (C) Give the structures of the following 4
   • (p) 2,4’-Diamino diphenyl
   • (r) 7-Methoxyspiro [4,5] decane
   • (s) 1-Chloro-2,3-pentadiene
   • (D) Complete the following reactions
   • a) cc
   • (D) Match the columns appropriately 3

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