ABSTRACT
CAPÍTULO 1: EL ENVEJECIMIENTO INDIVIDUAL
1.1. LA CONSTRUCCIÓN SOCIAL DE LA EDAD
1.1.2. Edad y Estructura social
of the following substrates would lead to maximum racemization ?
(A)
Et
CH3
Br
H (B)
CH3
D Cl H
(C)
H Cl
CH3
(D)
CD3
D Cl H
Sol.
9. The reaction of SOCl2 on alkanols to form alkyl chlorides gives good yields because
(A) Alkyl chlorides are immiscible with SOCl2 (B) The other products of the reaction are gaseous and escape out
(C) Alcohol and SOCl2 are soluble in water (D ) The re ac ti on d oe s not oc cur vi a intermediate formation of an alkyl chloro sulphite Sol.
10. Which of the following alcohol shows fastest reaction with HI ?
(A) OH
(B)
OH
(C) H C2
OH (D)
OH
Sol.
11. Arrange the following compounds in order of decreasing rate of hydrolysis for SN1 reaction
(I) CH2–Br
(II) H3C CH2–Br
(III) CH3 – CH2 CH2–Br
(IV) CH CH2–Br
CH3
CH3
(A) II > III > IV > I (B) IV > III > II > I (C) III > IV > II > I (D) I > II > III > IV Sol.
ALKYL HALIDE
12. For the given reaction ;
R – C – X
Which substrate will give maximum racemisation
(A) C H – C – Br6 5
13. Which of these dehydrates most readily when reacts with conc. H3PO4.
Major product (P) is :
(A) CH — C — C — CH3 3
15. Which of following halides gives fastest elimination reaction when it is treated with
ALKYL HALIDE Sol.
16. Which alkyl bromide will yield only one alkene upon E2 elimination ?
(A) Br
(B) Br
(C) Br
(D) Br Sol.
17. Cl
I
Cl
II
Cl
III which is most easily dehydrohalogenated ?
(A) I (B) II
(C) III (D) All with same ease Sol.
18. Correct order of yield of Hofmann alkene in following reaction will be
CH CH CHCH3 2 3
| X
X may be F, Cl Br or l
(A) F > Cl > Br > l (B) l > Br > Cl > F (C) Cl > F > Br > l (D) l > Br > F > Cl Sol.
19. Predict the major product of the following reaction :
CH CH CHCH OH3 2 2
| CH3
H SO2 4 heat
(A) CH CH C = CH3 2 2
CH| 3
(B) CH3CH = C(CH3)2 (C) CH3CH = CHCH2CH3 (D) (CH3)2CHCH = CH2 Sol.
20.
OH
conc. H SO2 4
major product
having H
(A) 12 H (B) 8 H
(C) 4 H (D) 11 H
Sol.
21. Which of the following compound will not undergo Nucleophillic substitution reaction.
(A) Cl
(B)
Cl
(C)
Cl
(D)
Br
ALKYL HALIDE
23. Statement 1 : On moving 1° to 3° alkyl halide rate of E2 increases while rate of SN2 decreases Statement 2 : E2 reaction give element effect respect to halogen.
(A) Statement-1 is true, statement-2 is true and statement -2 is correct explanation for statement-1.
(B) Statement-1 is true, statement-2 is true and statement-2 NOT the correct explanation for statment-1
(C) Statement :1 is true, statement-2 is false.
(D) Statement : 1 is false, statement -2 is above reaction is
(A)
ALKYL HALIDE Sol.
26. SN1 is a two-step reaction. For each step, there has to be a transition state. Which of the following structures represent correctly the transition state of first step
(A)
R...L
(B)
R...L
(C)
R...Nu
(D)
R...Nu
Sol.
27. Which one of the following compounds will give enantiomeric pair on treatment with HOH?
(A) C H – C – I6 5 C H2 5
C H2 5
(B) CH – C – Br3 CH3
C H2 5
(C) C H – C – Br6 5 H
D
(D) C H – C – Br2 5 C H2 5
CH3
Sol.
28. Which of the following compounds is most rapidly hydrolysed by SN1 mechanism
(A) C6H5Cl (B) Cl – CH2 – CH = CH2 (C) (C6H5)3CCl (D) C6H5CH2Cl
Sol.
29. Which will give white ppt. with AgNO3 ?
(A) Cl (B) Cl
(C) CH Cl2 (D) Both A and C Sol.
30.
Cl
Cl
NaOH
excess A. A is :
(A) O
OH
(B) Cl
OH
(C) OH
OH
(D) OH
Cl Sol.
ALKYL HALIDE
Products of above reaction is
(A) CH — I + CH — C — OH3 3
34. Which of the following carbocation will undergo rearragement ?
35. Which of following is dehydrating agent ? (A) conc. H3PO4 (B) P2O5
(C) POCl3 (D) All Sol.
ALKYL HALIDE
36. CH — CH — CH — C — CH3 2 2 3
CH3 Br
Identify all possible product obtained by E2 reaction ?
(A) CH3 — CH2 — CH2 — C = CH2 CH3
(B) CH3 — CH2 –CH= C CH3
CH3
(C) both (A) and (B) (D) none of these Sol.
37.
OH H+
(A)
major
Br2 CCl4
(B)
Product (B) is (A) meso (B) Racemic (C) Diastreomer
(D) optically active single products Sol.
38. M aj or p roduct of the re ac ti on i s
CH — C — CH — CH3 2 3 H
Br
alc. KOH
(A) Butene-1 (B) Trans-2-butene (C) cis-2-butene (D) Butyne-1
Sol.
39. In order to accomplish the following conversion, what reagent and conditions would be required
?
Cl
?
(A) Cold sodium hydroxide (B) Hot conc. sodium hydroxide (C) Potassium t-butoxide and heat (D) Hot water
Sol.
ALKYL HALIDE
JEE ADVANCED ( OBJECTIVE )
E XERCISE – II
1. Nu + C
S 2N
[TS] C + L
Which of the following figures represent correctly the structure of transition state in this reaction?
(A) [ Nu C
(B) [ Nu C
(C) either (A) or (B) depending upon situation (D) none of these
Sol.
2. From each of the following pairs select the compound that will react faster with sodium iodide in acetone
(a) 2-Chloropropane or 2-bromopropane
I II
(b) 1-Bromobutane or 2-bromobutane
I II
(A) (a)-I, (b)-I (B) (a)-I, (b)-II (C) (a)-II, (b)-I (D) (a)-II, (b)-II Sol.
3. Which of the following compound will be most reactive for SN1 and SN2 reactions
(A) I
O (B)
Cl O
(C) Br
O (D)
Cl
O Sol.
4. Best method for preparation of
CH — O — C — CH3 3
|
| CH3
CH3
by williamson’s ether
synthesis is
(A) CH O + CH — C — Br3 3
|
| CH3
CH3
(B) CH — CH — O + CH — CH — Br3 3
| CH3
| CH3
(C) CH — C — O + CH — Br3 3
|
| CH3
CH3
(D) CH — C — OH + CH — Br3 3
|
| CH3
CH3
ALKYL HALIDE Sol.
5. In the acid catalyzed dehydration of alcohols to alkenes, the intermediate species formed is (A) Free radical (B) Carbocation
(C) Carbanion (D) Carbene Sol.
Comprehension (Q.6 to 9)
(A) Cl (B) Cl
(C) Cl (D) CH3–Cl
6. Most reactive towards SN1 reaction Sol.
7. Most reactive towards SN2 reaction ? Sol.
8. Most reactive towards E2 reaction ? Sol.
9. Most reactive towards E1 reaction ? Sol.
10.
Br
Br
Zn + ZnBr2
This reaction is a case of
(A) -elimination (B) -elimination (C) -elimination (D) none of these Sol.
11.
Br
The major products obtained when this substrate is subjected to E2 reaction will be
(A) (B)
(C) both (A) and (B) (D) none of these Sol.
ALKYL HALIDE
12. Which of following cannot undergo an E2 reaction ?
(A)
H C3 CH Br2
(B)
CH3 H C3 Br
(C)
CH3
CH Br2
(A) A (B) B
(C) C
(D) None (all can undergo an E2 reaction) Sol.
13. Which alkylbromide will yield-3-methyl-1-hexene as the major product upon treatment with potassium t-butoxide in t-butyl alcohol (solvent) ?
(A) Br
(B)
Br
(C)
Br (D)
Br Sol.
14.
CH3
Cl
Total number of SN1 products of given compound are
(A) 3 (B) 4
(C) 5 (D) 6
Sol.
15.
Br CH3
CH3
The major product obtained when this substrate is subjected to E2 reaction will be
(A)
CH3
CH3
(B)
CH3 CH2
(C) both (A) and (B) (D) none of these Sol.
16. If the following E2 reaction proceeds through an anti-periplaner transition state, what products are expected ?
Cl CH3
(A) Only 3-methylcyclohexene (B) Only 1-methylcyclohexene
(C) The major product is 3-methylcyclohexene and the minor product is 1-methyl cyclohexene (D) The major products is 1-methylcyclohexene and the minor product is 3-methyl cyclohexene
ALKYL HALIDE products is :
(A)
Product (X) and (Y) respectively is (A) 1-butene, trans-2-butene (B) 1-butene, cis-2-butene (C) cis-2-butene, 1-butene (D) trans-2-butene, 1-butene
Sol.
19.
CH3 Br CH3
The major product obtained when this substrate is subjected to E1 reaction will be
(A)
(D) none of these
Sol.
20. Consider the given reaction
H — C — OTs
Which of following statement are correct for above reaction.
(A) Product formation takes place due to the breaking of O— Ts
(B) The reaction SN2 (C) The reaction is SN1
(D) Configuration of product is (R)
ALKYL HALIDE Sol.
21. Which are possible products in following CH3 compound (p) is
(A)
25.
Paragraph for Question Nos. 11 to 13 (3 questions) :
Dehydration require an acid catalyst to protonate the hydroxy group of the alcohol and convert it into good leaving group. Loss of water followed by a loss of a proton, given the alkene an equilibrium is stablished between reactants and products.
OH
26. To improve the yield of above reaction which of following is correct.
(A) High temperature (B) Distillation dehydration of alcohols in acids catayzed reaction.
ALKYL HALIDE
29. Column I Column II
Primary alkyl bromide SN2 relative rate
(A) CH3 — CH2 — Br (P) 10–5
(B) Me — CH2 — CH2 — Br (Q) 10–2
(C) Me — CH — CH — Br2
| Me
(R) 0.8
(D) Me — C — CH — Br2
| Me Me|
(S) 1 Sol.
30. Column I Column II
Alkyl—P—toluene sulfonate Ethanolysis relative (A) CH3 — CH2 — OTs (P)1010
(B) H2C = CH — CH2 — OTs (Q) 105
(C) Ph — CH2 — OTs. (R) 400
(D) Ph — CH — OTs
| Ph
(S) 35
(E) Ph3C — OTs. (T) 1
Sol.
31. Substrate E2 elimination SN2 — substitution
(A) CH3 — CH2 — Br (P) 1 (W) 0
(B) (CH3)2CH — Br (Q) 80 (X) 20
(C) (CH3)3CBr (R) 100 (Y) 90
Sol.
ALKYL HALIDE
32. Reaction Reaction rate of reaction
(A) HO + R — CH — I2 (P) 1 (B) HO + R — CH — Br2 (Q) 200 (C) HO + R — CH — Cl2 (R) 10,000 (D) HO + R — CH — F2 (S) 30,000 Sol.
33. column I Column II
Alkyl-bromide Relative rate of SN1
(A) CH — C — Br3
|
| CH3 CH3
(P) 1
(B) CH — CH — Br3
| CH3
(Q) 11.6
(C) CH3 — CH2 — Br (R) 1,200,000
Sol.
34. column I Column II
Solvent Relative rate of SN1
(A) 100% water (P) 1200
(B) 80% water + 20% ethanol (Q) 400
(C) 50% water + 50% ethanol (R) 60
(D) 20% water + 80% ethanol (S) 10
(E) 100% ethanol (T) 1
Sol.
ALKYL HALIDE
35. Match List-I with List II for given SN2 reaction & select the correct answer from the codes given below Z—CH Br + CH O 2 3 Z—CH OCH + Br 2 3
List I List II (relative reactivity)
(A) H— (P) 0.1
(B) CH3— (Q) 3
(C) C2H5— (R) 1
(D) CH3
CH3
CH— (S) 100
Sol.
36. Match List I with List II and select the correct answer from codes given below.
List I List II
(A) CH3 – O – SO2CH3 + C2H5O (P) CH3 — CH2 — PH2 (B) CH3 – CH2 – I + PH3 (Q) CH2 — O — C2H5 (C) HC C Na + CH3 – CH2 – Br (R) CH3 — O — CH3 (D) CH3 – Cl + CH3 – O (S) CH C — CH2 — CH3 Sol.
37. Column I and Column II contains four entries each. Entries of column I are to be matched with some entries of columnII. One or more than one entries of column I may have the matching with the same entries of column II and one entry of column-I may have one or more than one matching with entries of column II.
column I Column II
(A) EtOH
I (P) SN2 reaction
(B) CH — CH— CH Br3 2
l CH3
EtO EtOH
(Q) E1 reaction
(C)
CH3
CH3
Br
H H CH3
CH OH3 (R) E2 reaction
(D) CH — CH — Cl3 CH3
| CH —C—O3
O
(S) SN1 reaction
ALKYL HALIDE Sol.
38. Nu + Me—OTs DMF
25° Me—Nu + TsO
This is a SN2 reaction where nucleophile attack Me—OTs in the rate determining step to give the product. Rate of this reaction increases with concentration as well as nucleophilicity of the nucleophile . Match the column I with column II for the above reaction.
Column I Column II
(Nucleophile) (Relative rate)
(A) F (P) 3.25
(B) Cl (Q) 6.25
(C) Br (R) 1.0
(D) I (S) 7.75
Sol.
39. Match List I with List II (no. of structural isomers produced in -E2 elimination) and select the correct answer.
List I List II
(A)
H C3 H C3 CH3
CH3 Br
(i) Three
(B) H C3 Br
CH3
CH3
(ii) Zero
(C)
Br
CH3
CH3 H C3
H C3
(iii) One
(D)
Br CH3 CH3
H C3 (iv) Two
(a)(b)(c)(d) (a)(b)(c)(d)
(A) (i)(ii)(iv)(iii) (B) (iv)(iii)(i)(ii) (C) (iv)(iii)(ii)(i) (D) (i)(iii)(iv)(ii)
ALKYL HALIDE Sol.
40. Match the column
(A)
O — CH — CH2 3 H O3 +
(W) One of product is Ph — OH
(B)
O
H O3 +
(X) One of product is CH3 — CHO
(C) O H O3 +
(R) One of product is 2° alcohol
(D) O H O3 +
(Z) No-reaction
Sol.
ALKYL HALIDE
41. column I Column II
(A) O H O3 +
(P) No reaction
(B) CH — C — O — CH —CH3 3
| |
|
CH3 CH3
CH3
H O3 +
(Q) CH — C — OH3
|
|
CH3
CH3
is one of the
product of the reaction
(C) O — C — H O3 +
CH3 CH3 CH3
(R)
OH
is one the product
Product of the reaction
(D) O — CH H O3 +
CH3
CH3
(S) CH — CH — OH3
| CH3
is one the product
product of the reaction Sol.
42. column I Column II
(A) C — C
H+
CH3 CH3 CH3
CH3
O
(P) Pinacol fashion reaction
(B) CH — C — C—CH3 3
| |
| | CH3 CH3
H SO2 4 OH OH
(Q) Pinacolic Diazotization reaction
(C) CH — C — C—CH3 3
| |
| | CH3 CH3
NaNO2 OH NH2
HCl (R) Pinacol-Pinacolone reaction
(D)
OH OH
TsCl
Pyrdine (S) Product formed is CH — C — CH—CH3 3
CH3 O
(T) Semipinacol reaction
ALKYL HALIDE Sol.
43. Column I Column II
(A) Best leaving group (P) F
(B) Best nucleophile in polal protic solvent (Q) Cl (C) Best nucleophilie in polar aprotic solvent (R) Br
(D) Weakest base (S) I
Sol.
44. Substitution Logistics :
You were asked to run a series of reaction in the lab with different experimental conditions. Based on the experimental observation you gathered (listed below), indicate which mechanism this evidence supports. (Check the appropriate box to correspond to your answer.)
No. Observation SN1 SN2 Both
1 The rate of the reaction decreased when the concentration of the Nu is decreased.
2 The rate of the reaction increased when the concetration of the RX was increased.
3 The rate increased when the X w as changed from Cl to I.
4 The products show ed a skeletal rearrangement.
5 The product showed inversion of cofiguration.
6 The Nu was changed from methoxide to isopropoxide and the rate descreased.
7 The RX was changed from 2° alkyl halide to a 2° allyl halide and the increased.
8 The solvent was swtiched from ethnol to acetone and the rate decreased.
ALKYL HALIDE
JEE ADVANCED
E XERCISE – III
1. Which of the following reaction is not possible (A) R – OH + NaBr R – Br + NaOH
(B) R – OH + HBr R – Br + H2O (C) both reaction are possible (D) both reactions are not possible Sol.
2. Which of the following compound will not undergo acid catalysed hydrolysis ?
(A)
O—CH3
(B)
O—Ph
(C)
O—CH CH2 3
(D)
O
Sol.
3.
Br
I
Br
II
Br
III
SN2 reactivity of these substrate, under identical conditions, will be in the order as (A) I > II > III (B) III > II > I (C) III > I > II (D) II > III > I Sol.
4. A gem dichloride is formed in the reaction except
(A) CH3CHO and PCl5 (B) CH3COCH3 and PCl5
(C)
OH OH
2PCl5
(D) PCl5
O
Sol.
5. Which of the following nucleophile will show minimum reactivity towards SN2 reaction (A) Me CO3 (B) MeO
(C)
H O
(D) Me CHO2
ALKYL HALIDE Sol.
6. Which of following compounds will show NGP ?
(A) SPh
H H
Cl
(B) H
PhS H
Cl
(C) H
Cl
(D) Cl H
Sol.
7.
OCH3
OCH3
(x) conc. HI
Value of x in above reaction is
(A) 2 (B) 3
(C) 4 (D) 5
Sol.
8.
OCH3
OCH3
(X)Conc.HI
x = moles of HI consumed value of x is
(A) 2 (B) 4
(C) 5 (D) 6
Sol.
9. Consider the reaction of HI with the following
I O
II
O
Which forms di -iodi de on reacti on wi th HI(excess)?
(A) I and II both (B) II only
(C) I only (D) none
Sol.
10. Ph – C H —C — CH3
Br CH3 CH3
EtOH (SN )1 (A)
Major-product (A) is
(A) Ph – C – H C – CH3 OEt CH3 CH3
(B) Ph – C —CH — CH3 OEt
CH3 CH3
(C)
Ph CH3
CH3 CH3
(D) Ph – C —C — CH3
H OEt CH3
CH3
ALKYL HALIDE Sol.
11.
CH3
Et OH
H SOCl2
(A). Product (A) in
(A)
CH3
Et Cl
H (B)
Et
CH3 Cl H
(C)
CH3
Et H
Cl (D)
Sol.
12. CH – C3 H2 – O – C = CH2
CH3
H O3
Products
are
(A) O
+ EtOH
(B) O
+ EtOH
(C) OH
+ EtOH
(D) OH
+ O
Sol.
13.
H O excess
3 X
O O
Structure of X is
(A)
HO H
HO O
(B)
OH O OH
H
(C)
O OH OH
(D)
HO HO HO
Sol.
ALKYL HALIDE
14. In the given reaction : Cl
15. Among the bromides I-III given below, the order of reactivity is SN1 reaction is
(I)
ALKYL HALIDE Sol.
18. H+
O
(B) , Give structure of (B)
(A)
O
(B) O
(C) (D)
O Sol.
19. t-Bu OTs
AcO Na+ (A) Major-product (A) is
(A) t-Bu OAc
(B) t-Bu
OAc
(C) t-Bu
(D) t-Bu
OAc Sol.
20. Ph — CH — CH2
| Br
Br|
(x) NaNH2 +
(x = No. of moles of NaNH )2
Value of x is
(A) 1 (B) 2
(C) 3 (D) 4
Sol.
ALKYL HALIDE
21. The energy profile of the given reactions.
CH — CH — CH3 3 H CH — CH — CH3 3
OH O
| |
H H
+
+
CH — CH — CH3 3 —H CH — CH = CH3 2
+ +
(A) E
rxn-coordinate
(B) E
rxn-coordinate
(C) E
rxn-coordinate
(D) E
rxn-coordinate
Sol.
22.
OH CH3
CH3 H+ (x)
Major product (X) is
(A)
CH3
CH3 (B)
(C) (D)
Sol.
23. Which of the following alcohols would be most likely to undergo dehydration with rearragement by a process involving a methyl migration (methyl shift only) ?
(A) OH
(B) OH
(C) OH(D)
OH Sol.
24.
O OH
H SO2 4
X, X is
(A) OH
(B)
OH
(C) O
(D)
OH
Sol. OH
ALKYL HALIDE