| 摘要 |
The present invention provides novel pregnane derivatives of the formula: <IMG> (I) and a process for its production, for use as synthetic intermediates for the production of vitamin D3 derivatives having a hydroxy group in the 1.alpha.-position such as 1.alpha.-hydroxy-vitamin D3. In the above formula (I), A1 is in the .alpha.configuration and represents a hydrogen atom or a hydroxyl group, and A2 is such that where A1 is in the .alpha.-configuration and represents a hydrogen atom, A2 is in the .beta.-configuration and represents a hydroxyl group, an acyloxy group, a lower alkoxycarbonyloxy group, an N-lower alkylcarbamoyloxy group, an N-arylcarbamoyloxy group, an N,N-di(lower alkyl) carbamoyloxy group, a tri-(lower alkyl or phenyl) substituted silyloxy group, an alkoxymethoxy group or alkoxymethoxy group substituted by methoxy and that where A1 is in the .alpha.-configur-ation and represents a hydroxyl group, A2 is in the .beta.-configuration and represents a hydrogen atom, or A1 and A2 jointly represent an oxo group (=O); D1 is in the .alpha.-config-uration and represents a hydroxyl group, an acyloxy group, a lower alkoxycarbonyloxy group, an N-lower alkylcarbamoyloxy group, an N-arylcarbamoyloxy group, an N,N-di(lower alkyl)carbamoyloxy group, a tri-(lower alkyl or phenyl) substituted silyloxy group or an alkoxymethoxy group, alkoxymethoxy group substituted by methoxy, and D2 is in the .alpha.-configuration and represents a hydrogen atom, or D1 and D2 jointly represent an epoxy group (-O-) which is in the .alpha.configuration or a single bond; D3 is in the .alpha.-configuration and represents a hydrogen atom, D4 is in the .alpha.-configuration and represents a hydroxyl group, D5 is in the .alpha.-configuration and represents a hydrogen atom, D6 is in the .alpha.-configuration and represents a hydroxyl group, a lower alkoxycarbonyloxy group, an acyloxy group, an N-lower alkylcarbamoyloxy group, an N-arylcarbamoyloxy group or an N,N-di(lower alkyl)carbamoyloxy group, D7 is in the .beta.-configuration and represents a hydrogen atom; provided that D3 and D4 may jointly represent an epoxy group (-O-) which is in the .alpha.-configuration or a single bond, D4 and D5 may jointly represent a single bond, D5 and D6 may jointly represent an epoxy group (-O-) which is in the .alpha.-configuration or a single bond, and D6 and D7 may jointly represent a single bond; and X1 and X2 each is a lower alkoxy group or jointly represent a lower alkylenedioxy group or an oxo group (=O); with the proviso that, when D4 and D5 jointly represent a single bond, D6 and D7 jointly represent a single bond, D2 represents hydrogen, D3 represents hydrogen, D1 represents a hydroxyl group, a C1-4 acyloxy group or a C1-4 alkoxy carbonyl group, and A1 is hydrogen or hydroxyl, A2 is hydroxyl, a C1-4 acyloxy group or a C1-4 alkyloxy carbonyl group, X1 and X2 jointly represent an oxo group (=O).
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