| 摘要 |
24,24-Difluoro-26,27-dimethylvitamin D3 derivatives represented by formula: <IMAGE> (I) wherein X represents a hydrogen atom or a hydroxyl group. These compounds are prepared by irradiating 24,24-difluoro-26,27-dimethylcholesta-5,7-diene-(1 alpha ,)3 beta , 25-di- or triol with ultraviolet light, and is useful for the prevention or treatment of, for example, calcium pathobolism or osteoporosis. |
