| abstract |
NEW MATERIAL:A compound of formula I (R is H or OH, the wavy line represents the carbon atoms at the 24-position to be in the R- or S- configuration or a mixture of the R- with S-configurations). n EXAMPLE: 24(R)-25-Dehydro-1α,24-dihydroxyvitamin D 3 . n USE: A calcium regulating agent useful as a remedy for osteopathy, e.g. osteoporosis or osteomalacia, etc. due to the abnormal calcium metabolism. n PREPARATION: 24-Oxo-25-dehydrovitamin D 3 of formula II (R 1 is H, OH or protected OH; R 2 is H or a protecting group) is reduced with a boron hydride compound, e.g. sodium boron hydride, in an organic solvent at 5W50°C, and if necessary the protecting group is removed from the hydroxyl group to afford the aimed compound of formula I . n COPYRIGHT: (C)1984,JPO&Japio |