Allene and biphenyl derivatives

Question

Question 1:

a) Give an account of optical activity in allene and biphenyl derivatives.
b) Describe the relative stabilities of chair and boat conformations of cyclohexane.

Question 2:

a) What are carbocations? Describe their characteristics, stability and structure.
b) Describe Hammett equation and linear free energy relationship.
c) Describe the factors affecting the relative reactivity in the substitution reactions.

Question 3:

a) Write a note on:

• Diazonium coupling
• Gattermann – Koch reaction.

b) What are free radicals? Describe their characteristics, structure and stability?

c) Write a note on allylic Bromination with proper examples.

Question 4:

a) Describe the following:

• Perkin reaction
• Grignard reagent
• Claisen condensation.

b) Discuss different factors that affect the extent of E¹ and E² eliminations.

c) Write a note on E_1CB reaction with proper examples.