Substitution, Elimination and Addition Reactions - Structure-Reactivity Correlations and Organic Reaction Mechanisms - Life Sciences Previous Year Questions

1

2007 · Life Sciences · Structure-Reactivity Correlations and Organic Reaction Mechanisms · Substitution, Elimination and Addition Reactions

Life Sciences (XL) 2007

The product ‘P’ formed in the following reaction is

A

Benzophenone (C₆H₅COC₆H₅)

B

Benzaldehyde (C₆H₅CHO)

C

2-hydroxy-2-phenylacetaldehyde (C₆H₅CH(OH)CHO)

D

Phenylacetaldehyde (C₆H₅CH₂CHO)

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2

2007 · Life Sciences · Structure-Reactivity Correlations and Organic Reaction Mechanisms · Substitution, Elimination and Addition Reactions

Life Sciences (XL) 2007

The order of reactivity of the following aldehydes with a nucleophile is (I) HCHO, (II) CH₃CHO, (III) C₆H₅CHO, (IV) Cl₃CCHO

A

I > II > III > IV

B

IV > I > II > III

C

IV > III > II > I

D

I > IV > II > III

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3

2007 · Life Sciences · Structure-Reactivity Correlations and Organic Reaction Mechanisms · Substitution, Elimination and Addition Reactions

Life Sciences (XL) 2007

Which of the following olefins leads to a racemic mixture of the diol product upon cis-dihydroxylation?

A

H₂C=CH₂

B

cis-CH₃CH=CHCH₃

C

trans-CH₃CH=CHCH₃

D

CH₃C(CH₃)=C(CH₃)CH₃

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4

2007 · Life Sciences · Structure-Reactivity Correlations and Organic Reaction Mechanisms · Substitution, Elimination and Addition Reactions

Life Sciences (XL) 2007

The major product 'Q' formed in the following reaction is
\[\text{C}_6\text{H}_5\text{COOEt} \xrightarrow{\text{(i) MeMgBr (excess)}} \xrightarrow{\text{(ii) H}^+, \text{Heat}} \text{Q}\]

A

\(\text{C}_6\text{H}_5\text{COCH}_3\)

B

\(\text{C}_6\text{H}_5\text{C(OH)(CH}_3\text{)}_2\)

C

\(\text{C}_6\text{H}_5\text{CH=CHCH}_3\)

D

\(\text{C}_6\text{H}_5\text{CH}_2\text{CH=CH}_2\)

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5

2007 · Life Sciences · Structure-Reactivity Correlations and Organic Reaction Mechanisms · Substitution, Elimination and Addition Reactions

Life Sciences (XL) 2007

The major product 'R' formed in the following reaction sequence is
\[\text{Cl-C}_6\text{H}_4\text{-COOH} \xrightarrow{\text{HNO}_3/\text{H}_2\text{SO}_4} \xrightarrow{\text{Sn-HCl}} \xrightarrow{\text{NaNO}_2/\text{H}_2\text{SO}_4} \xrightarrow{\text{H}_2\text{O}} \text{R}\]

A

B

C

D

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6

2007 · Life Sciences · Structure-Reactivity Correlations and Organic Reaction Mechanisms · Substitution, Elimination and Addition Reactions

Life Sciences (XL) 2007

The following optically active compound undergoes racemization upon reaction with NaI in acetone.
\[\text{Ph-CH(I)-CH}_3 \xrightarrow{\text{NaI, Acetone}} \text{?}\]
The pathway followed by the reaction is

A

S_N1

B

S_N2

C

E1

D

E2

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7

2007 · Life Sciences · Structure-Reactivity Correlations and Organic Reaction Mechanisms · Substitution, Elimination and Addition Reactions

Life Sciences (XL) 2007

The structure of 'S' is

A

\(\text{CH}_3\text{COCH}_2\text{COOEt}\)

B

\(\text{CH}_3\text{COCH(CH}_3\text{)COOEt}\)

C

\(\text{CH}_3\text{CH(OH)CH}_2\text{COOEt}\)

D

\(\text{CH}_3\text{COCOCH}_2\text{COOEt}\)

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8

2007 · Life Sciences · Structure-Reactivity Correlations and Organic Reaction Mechanisms · Substitution, Elimination and Addition Reactions

Life Sciences (XL) 2007

The name reaction by which the product 'S' may be readily prepared is

A

Aldol condensation

B

Benzoin condensation

C

Claisen condensation

D

Perkin condensation

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9

2008 · Life Sciences · Structure-Reactivity Correlations and Organic Reaction Mechanisms · Substitution, Elimination and Addition Reactions

Life Sciences (XL) 2008

Which of the following acids is used for the preparation of cyclohexene from cyclohexanol?

A

Conc. \(HNO_3\)

B

48% HBr

C

85% \(H_3PO_4\)

D

\((COOH)_2\)

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10

2008 · Life Sciences · Structure-Reactivity Correlations and Organic Reaction Mechanisms · Substitution, Elimination and Addition Reactions

Life Sciences (XL) 2008

The major product in the above reaction is

A

1-(bromomethyl)cyclohex-1-ene

B

1-bromo-1-methylcyclohexane

C

1-(bromomethyl)cyclohexane

D

1-bromo-1-(bromomethyl)cyclohexane

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11

2008 · Life Sciences · Structure-Reactivity Correlations and Organic Reaction Mechanisms · Substitution, Elimination and Addition Reactions

Life Sciences (XL) 2008

Which one of the following will lactonize in presence of acid?

A

2-hydroxycyclohexanecarboxylic acid

B

3-hydroxycyclohexanecarboxylic acid

C

4-hydroxycyclohexanecarboxylic acid

D

2-methyl-4-hydroxycyclohexanecarboxylic acid

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12

2008 · Life Sciences · Structure-Reactivity Correlations and Organic Reaction Mechanisms · Substitution, Elimination and Addition Reactions

Life Sciences (XL) 2008

The major condensation product in the reaction of benzaldehyde with excess amount of acetone in presence of dilute NaOH solution is

A

4-phenylbut-3-en-2-one

B

1,5-diphenylpenta-1,4-dien-3-one

C

4-methyl-3-penten-2-one

D

4-hydroxy-4-phenylbutan-2-one

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13

2008 · Life Sciences · Structure-Reactivity Correlations and Organic Reaction Mechanisms · Substitution, Elimination and Addition Reactions

Life Sciences (XL) 2008

The appropriate reagent (O) required for this transformation is

A

KOH / EtOH

B

NaOMe / MeOH

C

NaI / Acetone

D

NaNH₂

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14

2008 · Life Sciences · Structure-Reactivity Correlations and Organic Reaction Mechanisms · Substitution, Elimination and Addition Reactions

Life Sciences (XL) 2008

The alkene will be produced as

A

P exclusively since it is going through E2 mechanism

B

Q exclusively since it is going through E2 mechanism

C

Equal amount of P and Q since it is going through E1 mechanism

D

P as major amount since it is going through E1cB mechanism

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15

2009 · Life Sciences · Structure-Reactivity Correlations and Organic Reaction Mechanisms · Substitution, Elimination and Addition Reactions

Life Sciences (XL) 2009

Identify the major product Q formed in the following reaction: \( (CH_3)_2CHCH_2Br \xrightarrow{NaOEt \, EtOH} Q \)

A

\(CH_3CH(OEt)CH_2CH_3 \)

B

\((CH_3)_2CHCH_2OEt \)

C

\((CH_3)_2COEt \)

D

\((CH_3)_2C=CH_2 \)

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16

2010 · Life Sciences · Structure-Reactivity Correlations and Organic Reaction Mechanisms · Substitution, Elimination and Addition Reactions

Life Sciences (XL) 2010

Structure of the compound Y in the following reaction sequence is

A

Bromobenzene

B

Benzene

C

Cyclohexadiene

D

Cyclohexene

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17

2010 · Life Sciences · Structure-Reactivity Correlations and Organic Reaction Mechanisms · Substitution, Elimination and Addition Reactions

Life Sciences (XL) 2010

The structure of X in the above reaction sequence is

A

MeO-C₆H₄-COCH₃

B

MeO-C₆H₄-OCOCH₃

C

MeO-C₆H₄-CH₂COCH₃

D

MeO-C₆H₄-OCOCH₂CH₃

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18

2010 · Life Sciences · Structure-Reactivity Correlations and Organic Reaction Mechanisms · Substitution, Elimination and Addition Reactions

Life Sciences (XL) 2010

The structure of Y in the above reaction sequence is

A

MeO-C₆H₄-COOH

B

MeO-C₆H₄-Br

C

MeO-C₆H₄-CH₂OH

D

MeO-C₆H₄-Br (para)

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19

2011 · Life Sciences · Structure-Reactivity Correlations and Organic Reaction Mechanisms · Substitution, Elimination and Addition Reactions

Life Sciences (XL) 2011

The major product for the following reaction is
Benzene + (CH3)2CHCH2Cl --(AlCl3)--> ?

A

Benzene ring with -CH3 and -CH(CH3)2 substituents (ortho/para)

B

Benzene ring with -CH2CH(CH3)2 substituent

C

Benzene ring with -C(CH3)3 substituent

D

Benzene ring with -CH2Cl and -CH(CH3)2 substituents

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20

2011 · Life Sciences · Structure-Reactivity Correlations and Organic Reaction Mechanisms · Substitution, Elimination and Addition Reactions

Life Sciences (XL) 2011

The above reaction is an example of

A

addition reaction

B

bimolecular elimination reaction (E₂)

C

unimolecular substitution reaction (SN₁)

D

bimolecular substitution reaction (SN₂)

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