M. Phil Ph.D. Course Work Examination June July 2017
CHEMISTRY (Paper II)
Recent Trends in Organic Chemistry
Day Date: Wednesday, 28-06-2017 Max. Marks: 100
Time: 11.00 AM to 02.00 PM
Instructions: Attempt in all five questions.
All the questions carry equal marks
Figures to the right indicate full marks.
Q.1 Give an account of the stereochemistry of ring fusion in Yohimbine. 10
Solve any two of the following: 10
Describe McLafferty rearrangement.
Explain mechanism and applications of Hunsdiecker reaction.
How will you differentiate the following isomers with the help of
NOESY experiments?
Q.2 Describe important features of the mass spectrum of primary,
secondary and tertiary alcohols. Write fragmentation modes of
various types of alcohols with suitable examples.
10
Solve any two of the following: 10
Give an effect of angle strain on vibrational frequency in IR
spectroscopy.
Describe Sonogashira coupling reaction with examples.
Write reaction mechanism and applications of N-Bromosuccinimide.
Q.3 Describe chemoselectivity and regioselectivity in organic reactions
with two suitable examples.
10
Solve any two of the following: 10
Assign the structure for compound shows following data M. F.
C8H11N
IR 3400, 3000, 1600, 1500, 750, 700 cm-1.
1HNMR 6.5 7.5 5H
3.3 1H
3.1 2H
1.2 3H
Assign the structure for compound showing following data. M.F.
C8H7OCl
IR 3300, 1690, 1600, 1500, 830 cm-1.
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SLR-OP-68
1HNMR 2.5 3H
7.3 J=8H2, 2H
7.9 J=8H2, 2H
Mass 154/156
139/141
111/113
The following triene on partial hydrogenation gives three
products. How uv spectroscopy and Woodward Fieser rules will
help to identify products?
Q.4 Describe Woodward and Prevost dihydroxylation with suitable
examples.
10
Solve any two of the following: 10
Assign the structure for compound showing following data. M.F.
C12H16O2
IR 1666, 2900 cm-1.
1HNMR 1.4 9H
3.8 3H
6.9 2H
7.8 2H
Mass 135, 107
Assign the structure for compound showing following data. M.F.
C4H8O2
uv: 210 nm
IR: 2984, 1741cm-1.
1HNMR 1.3 15mm
2.05 15mm
4.2 10mm
13CNMR: 14, 20, 60, 170
Mass 88,43, 29
Describe stereochemistry involved in SNi reaction with suitable
examples.
Q.5 Describe stereospecific and stereoselective reactions with suitable
examples.
10
Solve any two of the following: 10
What is meant by COSY experiments? Explain.
Discuss the prochirality of citric acid.
Write note on umpolung concept.