5079
Which of the
following compounds would be expected to show aromatic properties
(circle)? Explain your choice in each
case.
5098
Why is the pKa of cycloheptatriene
so much greater than that of cyclopentadiene?
5105
Predict which
compound would give the faster reaction.
Explain your answer.
5197
Azulene, the hydrocarbon
shown below, is blue and has a significant dipole moment of approximately 1.0 Debye.
(a) Show, by means of important resonance
structures, the direction in which you would expect the dipole moment to be.
(b) Comment on the factors which are most
important in giving azulene a high degree of
resonance stabilization.
(c) Azulene is quite
strongly basic; treatment with HBF4 produces a stable
isolable salt. What is its structure?
5275
Suggest how the
bonding electrons in imidazole account for its aromaticity.
imidazole