CHEMISTRY

Paper II
Time Allowed Three Hours IIMaximum Marks: 300I
INSTRUCTIONS
EfLCh question is printed both in':Hindi and
in English. Answers must written in the medium specified in the Admission Certificate issued to you, which must· be stated clearly on the' cover ofthe answer-book in the space provided for the purpose. No marks zpiU be given for the answers written in a medium 'other than thatspecifi,ed in the Admission Certificate.
Candidates should Questions no. 1 and .5 which are compulsory, and. any three of the remaining questions selecting at least one question from each Section.
Assume su'itable data if considered necessary
and indicate the same clearly.
The "number of marks . carried by. each
question is indicated at . the end of the
question.

Symbols and notations carry usual meaning,
unless otherwise indicated.

u:TF1 QJT NUH err rNT I
I
SECTION A

1. . -Answer the following,: lOx6=60
Which one of the following compounds 1S more basic? Explain with
I I



n -2

(CHa)2N (Ph N Ph
,32


Write the 'structures of the reaction from . succinimide with bromine ,and aq. KOH.


Acetolysis of compound is lOll times faster


than that of with retention of configuration. Account for this _observation.




How would you synthesise the following compound uSIng aldol condensation Give the structure of starting-material and the mechanism of ·the reaction.-­
csy
CHO
C-DTN--L-DIB 2 [Contd.]

1. lOx6=60
7ifflffi


o (1

(Ph (CHa)2NJlph

am KOH ..qit I
cit CfiT lOll TIT mm I &iRQI
H H

ThO ThO


h

CfiT Cl?f qM Ch1 3W:
I

CHO

3

How will you synthesise 1,3-pentadiene starting
from. piperidine?
,How would.yOll synthesise shown below using
Beckmann rearrangement reaction Show the
proper geometry of the intermediate.
C6H5

2.· Azulene possesses dipole moment 1·0 D and
electrophilic substitution. in it occurs at the
position-l of'the five membered ring. Provide
explanation. 20
One of"the following hydrocarbons is much more
acidic than the other two. Justify your answer
considering the stability of.their conjugate. bases. 20



.
(c):Explain the following with' reasons lOx2=20·

Electrophilic substitution ofpyrrole is easier than benzene.


Furan undergoes Diels -Alder reaction more readily than pyrrole.


C-DTN--l-DIB 4 [Contd,J
i
q;r

31N c.nr
q)f >fCfiR
q;tlf? I
C6H5 CONH-@-OCH3

2. q)T 1·0 D afu:
'tffq cn1 Wffii-l

20


1R 3m: it

2S




10x2=20
m cnr anfll'1 I
aNan, "-ij itffi mat
C-DTN--L-DIB 5 [Contd.] .
3. e Why is CN (cyanide ion) a highly specific catalyst
for the benzoin condensation Formulate the
product(s) in the following reaction with
mechanism 20
C6Hs -CHO (CHa)2 N KeN.?
•
Give the· mechanisms for the following
transformations: • 10x2=20


CNe
Br


The compound shown below can be synthesised from as .well as using alkoxide. Name the reaction and propose the mechanisms.
C6Rs -CH2 -CH2 -COOR

C6Hs-CH2-CO-CH2-CI





C6Hs -CO -eRa
C-OTN--L-DIB 6 [Contd.J
•

s
3. qirr 3WR) <rtfS4Cfi(q 3NIe: Cf)f fCHi.!"1 20
.. KCN
CsHs -CHO (CH3?2 ..
<rtfS4Cfi('q lOx2=20


Br

aTI Wfm ifT flCfi(1 I cnr '31tt I
C6H5 -CH2 CH2 -COOR

C6Hs-CH2-CO-CH2-Cl
.
C6Hs-CH(Cl)-CO-:CH3

C-DTN--L-DIB [Contd.]
4. "dl·pair of when treated'
with furnished dl-pair of
whereas the of erythro compound gave the
isomer." Explain with mechanism. 20
How would you carry out the following
transformations? Indicate the reagents used and
show-the mechanisms involved. 15x2=30.

Aniline Acrylaldehyde


•
-Alkaline hydrolysis of (C2H5)2 -CH2 -C2Hs produces (C2H5)2N-CH(C2Hs)-CH20Heasily.Accountfor the observation.
C-DTN--L-DIB 8 [Contd .J
cnr HBr d412{1{ f%7.n q)f UjOO mrr
"
*,P4Iq;qcil g3IT In
.t,
t

.J.",
l J I I I " 3lr1 CliT fcfrt1 JJChR' eWt 3ll I 15x2=30


(C2HS)2 -CH2 -C2H5 CfiT 3iltil;IT
(C2H5)2N q)f 3ttllG;"'l ChUil I Cf)l{0l I 10
C-DTN--L-DIB 9 IContd.l
·-
SECTION B
5. Answer the following lOx6=60
Give the structure and its conversion to with.mechanism for the following,transformation
hv. Q o

.

How Malaprade oxidation is used to determine cis-glycolic units in sugars? Illustrate with one example showing mechanism.


An organic .comporind of formula the following PMR data in 8 scale:


2·9 3·8 4H)and 1·8 (broad singlet, exchanged with D20, IH).
Suggest the structure of the compound 'assigning the reasons for the peaks.
How will you differentiate the following pairs by IR spectra. 5x2=10
.ci) R -COOCH3 and R·-CO -COR
CHa-CHO and
o

10 [Contd.l



5.. lOx6=60 ett B{oqO:II 31R CfiT' d'8CbI
hv !J. Q
0


-mu31f CJlT 51CfiI{
ifffiT ifRJ "Qq) t w.r I

3lTfUqq;.
PMRSTZT 2·9 Ct, 3·8 4H) 31R 1-8 D20, IH
cfit 31R ftl&U q;wrr
IDU 5x2=10
R-COOCHa R-CO-0 -COR
CRg-CRO aih: CH2 -.CH2


11 [Contd.l
Give the purpose of the following compounds in polymer chemistry:
.
Benzoyl peroxide
IIydroquinone
CC14


Ethyl mercaptan


Hydrogen peroxide


base peak appears at 105 for ofthe following compounds Band and at in/e 119 for the other two. Match th..e compounds with appropriate m/e for their base peaks.


"
. 6. Thermal cyclisation of cis) trans-2,4:-hexadiene
...
gives cis-3,4-dimethyl cyclobutene whereas trans, trans-2,4-hexadiene gives trans-3,4-dimethyl
t"
cyclobutene .by the conrotatory process. Explain using Woodward -Hoffmann rule.
C-DTN-·L-DIB· 12 [Contd.]

cir,



CCl4
"Qf2R1.


B '5fCR:. mm 10511, am, ap.:f mje 119lR mm t I Cf)f mje lfR1 m2f



6. q)f "5IGR CfiOT
,....
>milf -rnr cwrr I CfiT CfiT I 20
C-DTN--L-DIB 13 [Contd.]
How would you explain the transformation of butadiene to and by one route but and as shown by a different route? Give the mechanism for the transformation.
hv



V
sens. hv
+L1

A peptide was from phenylalanine, tyrosine and lysine in the sequential order by protecting first the amino group of phenylalanine. Write the ,.Structure of the peptide showing the reagents used in various steps. Will .the newly formed peptide be acidic-or basic? Give the reason. 20
7. ·(a) Explain why thermal.cycloaddition of two molecules qf ethylene to cyclobutene is forbidden b,u.t photochemically allowed. Explain this result by
'using HOMO-LUMO-concept. • 20
......
C-DTN--L-DIB 14 [C()ntd·.]
..f:n Tf<ITW, 1IT1f IDU ctT am CfiT 3R l1fTf CD) 3TItf >rcfiR: {Cqifl(QI I 20
hv
sens.

!hv CD) .

LJ

Cb1
q)T Tp.IT 2IT I oq{On if cir ett I I Ff> San mrrr· -qr I Cf)1<0 1 tstdl$l( I 20
.
7. fq) q<rr 0 1 31UJaTI CfiT tr0l "{Cq I HOMO-LUMO "CfiT -qU0lllOi I 20
C-DTN--L-DIB 15 [Contd.l



(n The exo-norborene as shown below when heated gives with complete retention of configuration ofthe migrating group. Explain showing the mechanism. 10


D

•

"Photo reaction of acetone with by 81 process gives cis and trans products, but with gives only one isomer." Explain. 10
NC
JiCN
(CH3)2C 0 1
. CN CN NC CN

CH
3
-""CN
.!(fCN
C-DTN·-L-DfB 16 IContd.l

fq). lfl1T cit Sl c4lij;:ft m2l TTtf Otif JIGR rIDChtii 10
A OAc
..
. D

H

qit.. 81(n Jmil:r IDT tWr am A dt:q"IG Cfi«fi W-T BJOilq4ql "5IGR W I"
10
NC .


)feN
(CH3)2C 0 ..
eN eN

eN
CH"
3


17 [Contd.J
".,.

.....
Predict the. structure of the products in.the folloWing reactions. Give the mechanism. 5x4=20
0 mCPBA




D Se02


0

Li
CaH7-C
liq. NH3


8. When acetone IS heated with NaOH a product is obtained which showed the following spectral features:
IR 1695; 1620 IH NMR 1·90 2·10 6·00 IH)

Deduce the structure ·of A and interpret the

C-DTN--L-DIB 1.8 [Contd.l
.
Ch1 ft{oq'1l I I 5x4=20 o
lP mCPBA.?
o
DSeOz


..


.
I I.


8. CfiT NaOH "1Jlf jfffiT

"f
..

"



I
I


d("qlG mm t,.
IR 1695, 1620 IH NMR 1·90 2·10 6·00 IH) 98, 83, 55 53, 43, 39
c€t q;r .31R :sTGT COT 312f -30
B 19 [Cohtd.l
Calculate the /...max for th¢, following-compounds
using Woodward -Fieser'rule
o

U

HO
OH
OJ? o
How would you explain the carbonyl stretching frequenCies given below the structure of the following compounds? • 15
o 06 6 dOl


1727 1754 1802 1825


20

I
I




HO·

OH

(IrI1

o
cnl· ."5f"ffi;:r cor 31TCf tl 15


6o 60 dO!

1754' 1802 1825
C-DTN--L-DIB ·21
I



300 II

>rH 3ik 3f7bft m 3fN :fflT 1iJlZI11 ·ffRi JfFf .fuMe fJt?fd57 .-rm-q f1tscH rrc:rr ..3ik: 1iJlZI11 Q5T Jffi!.Sl
rp: ?WFf rrr Ml/7 JfRT
i:n&e fR· 3fffiRstrl 1lT&Pf 31fdRfb 3Rl fd5m 1iJlZI11 ffRff 1JT! 3m mTI 3im ;nff filiiiJ I 1 3tk 5 3fH4/q! I mctt
l0-
WJlc0iP ?9U5 l?C5 .JrR grtctJ'<
ffFr·fi 3m cfJfJte l
?IT 3QCjffl Q5T i/4rj <tJBte (f2lT 3rjCfj) Ptfltt; Cb7f3te I ut4CfJ J!H 8J fffi! B4d 3Ffr#
1Tl! I ffiJflPll JRl ?fC5
.
.
3RWT Tf'lT I
Note: Engfish version of the Instructions is printed on the front cover of this question paper,