Ultrasound assisted remote functionalization of non-activated carbon atoms: Efficient in situ formation of tetrahydrofurans by sonolysis of bromohydrins with (diacetoxyiodo)benzene/I2

Article abstract of DOI:10.1016/S0040-4039(99)01849-3

Ultrasonic irradiation of bromohydrins in the presence of (diacetoxyiodo)benzene and I₂ generates alkoxyl radicals which lead in situ to intramolecular hydrogen abstraction on the C-19 non-activated carbon atoms in steroids producing tetrahydrofurans selectively in very good yields. Photolysis was less effective in promoting such conversions.