Which of the following alkyl free radicals is the most stable?

Step-by-step solution

The stability of alkyl free radicals is determined by hyperconjugation, which depends on the number of -hydrogen atoms attached to the sp^3 hybridized carbon atoms adjacent to the radical center. Greater the number of -hydrogens, greater is the number of hyperconjugative structures, and hence more stable is the free radical. Let us count the -hydrogens for each option: 1) ( CH ₃ )₃ C - C H ₂ has 0 -hydrogens. 2) CH ₃- CH ₂- C H - CH ₂- CH ₃ has 4 -hydrogens. 3) CH ₃- C H - CH ₂- CH ₂- CH ₃ has 5 -hydrogens. 4) CH ₃