Today my professor discussed carbon radical reactions and showed us an example where you could either have 6-exo-trig or 7-endo-trig. According to Baldwin Rules both reactions would be favorable howver 6-exo-trig occurs because although the process of 7-endo-trig would generate a secondary radical which is more stable than the primary radical formed by 6-exo-trig, the stability of the secondary radical is not enough to overcome the inherent kinetic reference of making a 6 over a 7 membered ring. Can anyone clarify the order of ring formation by carbon-centered radical reactions?
So far for cyclization kinetics I have: 5>6>7>3>4, can anyone confirm this?