From the reaction free energy diagram presented in Figure , we can see that benzyl alcohol A reacts with the tert-butyl base to form the K + salt B. This step of the reaction is favored, with a ΔG = -5.3 kcal/mol. Notably, this step can itself be skipped completely as the reaction was experimentally shown to proceed when starting directly from the K + salt. This also indicates that the tert-butyl base does not play a significant role in reaction steps following B. The salt proceeds to interact with molecular oxygen, which leads to oxidation and the formation of the radical C via hydrogen atom abstraction (HAT) depicted in TS B-C . The free energy barrier for this step is ΔG ‡ = 13.2 kcal/mol, while the formation of the C radical itself is favored (ΔG = -11.8 kcal/mol). With the formation of C, a peroxyl radical is liberated. In presence of water coming from the environment, the C E' complex (ΔG = -13.7 kcal/mol) is formed. The potassium ion assists proton abstraction from water, forming the radical D, which is strongly favored, with ΔG = -43.6 kcal/mol. The energy barrier for this step is given by TS C-D and D has a free energy of ΔG ‡ = 15.5 kcal/mol. D represents a key intermediate along four of the five reaction paths shown in Figure . For both C and D giso values were calculated, with giso,C=2.003 and giso,D=2.004. A radical species was also detected in EPR spectroscopy (giso=2.001, see Scheme 3) and our g-tensor calculations indicate that this structure must be either C or D or a mixture of both (See Figure for details).