a)
Interpretation:
The product formed when 2-hexyne reacts with 2 equivalents of bromine.
Concept introduction:
In addition reactions,
To give:
The product formed when 2-hexyne reacts with two molar equivalents of bromine.
b)
Interpretation:
The product formed when 2-hexyne reacts with 1 equivalent of HBr is to be predicted.
Concept introduction:
In addition reactions, alkynes when treated with two molar equivalents of a reagent yield the derivatives of the corresponding alkane as the product. With one molar equivalent of a reagent they yield a derivative of the corresponding alkene as the product. The addition to unsymmetrical alkenes follows Markovnikov regiochemistry. The negative part of the reagent adds on to the more highly substituted carbon in triple bond.
To predict:
The product formed when 2-hexyne reacts with 1 equivalent of HBr.
c)
Interpretation:
The product formed when 2-hexyne reacts with 1 equivalent of HBr is to be predicted.
Concept introduction:
In addition reactions, alkynes when treated with excess amount of a reagent yield the derivatives of the corresponding alkane as the product. The addition to unsymmetrical alkenes follows Markovnikov regiochemistry. The negative part of the reagent adds on to the more highly substituted carbon in triple bond.
To predict:
The product formed when 2-hexyne reacts with excess of HBr.
d)
Interpretation:
The product formed when 2-hexyne reacts with Li in ammonia.
Concept introduction:
Alkynes can be reduced by treatment with hydrogen in the presence of a catalyst. The hydrogenation occurs with anti stereochemistry to give a trans- alkene as product if Li in ammonia is used.
To predict:
The product formed when 2-hexyne reacts with Li in ammonia.
e)
Interpretation:
The product formed when 2-hexyne reacts with H2O, H2SO4 in the presence of HgSO4 is to be given.
Concept introduction:
When treated with H2O, H2SO4 in the presence of HgSO4 alkynes get hydrated to produce enols. The addition of water to unsymmetrical alkynes follows Markonikov regiochemistry while it cannot be applied in the case of symmetrical alkynes. The enols produced then undergo tautomerization to give a
To predict:
The product formed when 2-hexyne reacts with H2O, H2SO4 in the presence of HgSO4.
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Chapter 9 Solutions
Organic Chemistry
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- Organic ChemistryChemistryISBN:9781305580350Author:William H. Brown, Brent L. Iverson, Eric Anslyn, Christopher S. FootePublisher:Cengage Learning