Self-sensitized photooxygenation of 3, 4-dialkoxyfurans 3a-d with molecular oxygen and UV- or sunlight at room temperature gave vitamin C derivatives 2a-d in good to excellent yields. Furan 3c, having photodegradable protecting groups, was also photooxygenated to give l- ascorbic acid (1) in a “one-pot” reaction. Furthermore, a novel photolytic transformation was developed for deuteration of furan 3b at the C-2 position with D2O to give furan 3d in 95% ...
