CHEMISTRY
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PAPER ·II
SECTION A
Answer any four of the following (each answer in about 150 words)
3 of'7
(10 X 4 40)
(a)State the products with reason·whether these reactions will be either SN1 or SN2·
src='./qimages/1473-1a1.jpg'>
src='./qimages/1473-1a2.jpg'>
(iii)<img src='./qimages/1473-1a3.jpg'>

(b)Thermal inter-conversion of 5-hexatriene to cyclohexadiene under thermal takes place
by disrotation Explain showing M.O diagram.
(c)The rate of acid-catalysed hydration of two alkenes shown differ by a factor of over 7000 at
25 deg c Which isomer is more reactive and why?
<img src='./qimages/1473-1c.jpg'>

being heated with a solution of C2H5ONa in ethanol, compound A (C7H5Br) yielded a
mixture of two alkenes B and c. each having the molecular formula C7H14. Catalytic
hydrogenation of the major isomer B or the minor isomer C gives only 3-ethyl pentane.
Suggest structure for compound A. B and C consistent with observations.
(e)Bring out the following conversions and predict the reaction mechanism:
<img src='./qimages/1473-1e1.jpg'>
<img src='./qimages/1473-1e2.jpg'>

(2)(a)illustrate the mechanism involved in sigma tropic rearrangement with one suitable
example under thermal and photo-chemical conditions by FMO method.
Draw mechanisms for these two elimination reaction or epoxides
<img src='./qimages/1473-2b1.jpg'>
<img src='./qimages/1473-2b2.jpg'>

What are singlet and methyl nitrenes? Explain their additions to cisbutene-2.
Predict with reasoning which of the following compounds are classified as aromatic or non-
aromatic
<img src='./qimages/1473-2d.jpg'>

3.(a)What are the kinetic method used lo determine organic reaction mechanism?
(b)Bimolecular elimination of compound A is ten times slower than that of B. Explain with
reason
<img src='./qimages/1473-3b.jpg'>

(c)Show how kinetics is used to determine the mechanism of Benzoin condensation
(d)Explain the following interversion by correlation diagram method
<img src='./qimages/1473-3d.jpg'>

4.(a)Complete the following reactions and give its mechanism:
<img src='./qimages/1473-4a.jpg'>

(b)Discuss the aromaticity of Fulvenes and Azulenes.
(c)Explain the stepwise mechanism involved in the preparation of Methyl- isoquinoline by
Bischler-Napieralski method
Give the products and mechanism of Bayer Villager rearrangement on these carbonyl compounds with reasons
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src='./qimages/1473-4d2.jpg'>

SECTION B
5.Answer any four of the following {each m about 1$0 words) (10x4=40)
Describe the initiation, elongation and termination in RNA synthesis.
Differentiate between
Fine splitting,
Hyperfine splitting,
Superfine splitting.
Explain these ESR splittings with suitable examples.
(c)How will you distinguish the following three parts by the indicated spectroscopic methods?
delta-valerolactone and y-butyrolactone by IR.
trans-Stilbene and cis-Stilbene by NMR,
2-pentanone and 3-pentanone by ESIMS.
(d)Write the products formed in the following photochemical transformation

(e)Explain the formation of the products including stereo chemical aspects With possible
mechanism.
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src='./qimages/1473-5e2.jpg'>

6.(a)Explain the important applications of sodium borohydride as a reducing agent Explain With
mechanism the reaction of the following Compound.

(b)Give a brief account of primary, secondary, tertiary and quaternary structure of proteins with
suitable examples
(c)How is polyethylene manufactured? What are Its unique characteristics in relation to its
applications?
(d)Describe how is ESR spectroscopy used in the study of inorganic complex and free radicals.(10 X 40)

7.(a)Explain 1he formation of products,stereo chemical aspects and mechanism for the following
reactions

src='./qimages/1473-7a1.jpg'>
src='./qimages/1473-7a2.jpg'>
(iii)<img src='./qimages/1473-7a3.jpg'>

(b)How could data from a low resolution mass spectrum be used to distinguish between
C6H13Cl and C3H5Br?(10)
(c)How will you differentiate between the following pairs of compounds using lR spectra
(i)o-Hydroxy benzoic acid and m-Hydroxy benzoic acid;
(ii)CH3-CH2-CHO and OH2=CH-CH2OH;
(iii)<img src='./qimages/1473-7b3.jpg'>

8.(a)Calculate lamda max for a pie-pie* transition absorption band in UV spectra of the following
compounds:
src='./qimages/1473-8a1.jpg'>
src='./qimages/1473-8a2.jpg'>
(iii)<img src='./qimages/1473-8a3.jpg'>

(b)propose structure for the compound based upon the following spectral data
Mol formula C5H11N
:3400,3000,1400,1500,1600,750,700

mass(m/z) 121 and 106