Intramolecular hydrogen abstraction. Hypervalent organoiodine compounds, convenient reagents for alkoxyl radical generation
Abstract
The photolyses of 5α-cholestane-3β,6β-diol 3-acetate (1), 5α-cholestan-2β-ol (4), 5α-cholestan-4β-ol (8), (20R)-pregn-5-ene-3β,20-diol 3-acetate (19), (20S)-pregn-5-ene-3β,20-diol 3-acetate (21), and dihydrotigogenin 3-acetate (25) in the presence of iodine and various hypervalent organoiodine compounds lead to alkoxyl radicals which undergo intramolecular hydrogen abstraction to produce, in most cases, 1,4-iodohydrins and tetrahydrofuran derivatives.