The low activation energy pathways to the formation of the five major experimental products are summarized in Figure . 3. All products share the first two steps (1-1→2-1→3-3), then DHA is formed in a single step (shown in purple, with ∆G † max of 34.05 kcal/mol), while the other four products share two additional steps (3-3→4-4→5-1) before branching through the intermediates 6-1 and 6-2 (i.e., precursors to HEH and 3-hexulose, respectively). These latter branches are shown in the upper and lower part of Figure , respectively. In the discussion that follows several products can be formed through either branch with similar barrier and these branches will be referred to as the HEH and hexulose pathways.