Which of the following radicals is the most stable?

Rank the following radicals in decreasing order of stability. Classify each as primary, secondary, or tertiary.

a. The isopentyl radical,

b. The 3-methyl-2-butyl radical,

c. The 2-methyl-2-butyl radical,

d.

Use the information in Table 4-2 (p. 167) to rank the following radicals in decreasing order of stability.

For each set of reactive intermediates, rank them in order of reactivity (1 = most reactive).

(b)

Which of the following is the most stable radical?

What is the correct order of stability of the following alkyl radicals (from most stable to least stable): $\mathrm{tertiary}$, $\mathrm{secondary}$, $\mathrm{primary}$, $\mathrm{methyl}$?

Rank the following carbon radicals in order of decreasing stability: ${\mathrm{CH}}^3\cdot$ (methyl radical), $\mathrm{CH}{3}_2\mathrm{CH}\cdot$ (secondary radical), $\mathrm{CH}{3}_{3}C\cdot$ (tertiary radical), $\mathrm{CH}{3}_1\mathrm{CH}\cdot$ (primary radical).

Which of the following radicals formed by cleavage of a $C–H$ bond is the most stable in isobutane (${\mathrm{(CH}}_3{)}_3\mathrm{CH}$)?

Use the information in Table 4-2 to explain why toluene (PhCH₃) has a very high octane rating of 111. Write an equation to show how toluene reacts with an alkyl free radical to give a relatively stable radical.