| 摘要 |
Novel 1 alpha , 24-dihydroxycholecalciferol and derivatives thereof which are useful with reduced side-effects for the treatment of abnormal metabolism of calcium and phosphorus caused by liver failure, renal failure, gastrointestinal tract failure and parathyroid failure, and related bone diseases. Preparation of the novel 1 alpha , 24-dihydroxycholecalciferol and their derivatives starts from 1 alpha , 24-dihydroxycholesterol prepared by reacting 1 alpha , 2 alpha -epoxy-24-keto-cholesta-4,6-dien-3-one with an alkali metal and a proton donor in the presence of liquid ammonia or a liquid amine. Reaction of the 1 alpha , 24-dihydroxycholesterol with an allylic brominating agent, followed by contacting with a dehydrobrominating agent, affords 1 alpha ,3 beta , 24-trihydroxycholesta-5,7-diene derivative, which can then be converted to 1 alpha , 24-dihydroxycholocalciferol by ultraviolet irradiation in a organic solvent, followed by isomerization. Processes are also provided for separating 1 alpha , 24-dihydroxycholesterol into an (S)-epimer and an (R)-epimer, and also for separating at least one of 1 alpha , 3 beta , 24(S)-and 1 alpha , 3 beta , 24(R)-trihydroxycholesta-5,7-dienes from trihydroxycholesta-4,6-diene.
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