Ultrasound assisted zinc reactions in synthesis 2. A new Clemmensen-type reduction

Article abstract of DOI:10.1016/S0040-4039(00)60588-9

A mild and efficient method is described for the reduction of carbonyls to methylene groups. Under ultrasonic irradiation, deoxygenation of 3-oxosteroids with zinc dust in acetic acid or acetic acid/water was achieved in 15 minutes. The observed selectivity at C-3 in the presence of 17- and 20-oxo groups is discussed.