What are ambident nucleophiles?  Explain with an example.

2

(a)

Suggest a possible mechanism for the following reaction:
\(n-BuBr + KCN \xrightarrow{EtOH_2,\ H_2O} n-BuCN\)

2

(a)

Identify the compounds A, B, C and D in the following sequence of reaction:

 

2

(a)

Write the structural formulae of the organic compounds 'A', 'B', 'C' and 'D' in the following sequence of reaction

2

(a)

Why are haloarenes more stable than haloalkanes and undergo electrophilic substitution reaction at ortho and para positions?

2

(a)

Predict all the alkenes that would be formed by dehydrohalogenation of the following halides with sodium ethoxide in ethanol and identify the major alkene.
(a) Cyclohexylmethyl bromide
(b) 3-Bromopent-1-ene

2

(a)

Name the following halides according to IUPAC system and classify them as alkyl, allyl, benzyl(primary, secondary,tertiary), vinyl or aryl halides.
(i) CH₃CH=CHC(Br)(CH₃)₂
(ii) p-ClC₆H₄CH₂CH(CH₃)₂
(iii) m-ClCH₂C₆H₄CH₂C(CH₃)₃
(iv) o-Br-C₆H₄CH(CH₃)CH₂CH₃

2

(a)

Aryl chlorides and bromides can be easily prepared by electrophilic substitution of arenes with chlorine and bromine respectively in the presence of Lewis acid catalysts.  But why does preparation of aryl iodides requires presence of an oxidising agent?

2

(a)

Which of the following compounds(a) and (b) will not react with a mixture of NaBr and H₂SO₄. Explain why?

2

(a)

Draw other resonance structures

related to the following structure and find out whether the functional group present in the molecule is ortho, para directing or meta directing.

2

(a)

Which of the following haloalkanes reacts with aqueous KOH most easily?  Explain giving reason.
(i) 1-Bromobutane
(ii) 2-Bromobutane
(iii) 2-Bromo-2-methylpropane
(iv) 2-Chlorobutane

2

(a)

What are the IUPAC names of the insecticide DDT and banned in India and other countries?

2

(a)