Ring closure reactions were investigated in a combined computational (density functional theory) and experimental study, to uncover the origin of diastereoselection in 5-exo-trig cyclizations of methyl and tert-butyl-substituted 4-penten-1-oxyl radicals. Selectivity data were calculated on the basis of transition state theory, the Curtin–Hammett principle, and Maxwell–Boltzmann statistics, to provide an excellent correlation between computed and ...
