Blocked cholecalciferol and dihydrotachysterol 3 derivatives

DETAILED DESCRIPTION We have found that cholecalciferol and dihydrotachysterol.
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3 and their derivatives may be metabolically blocked by the presence of a halo or O-C.
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1-5 alkyl carbamate group in the 25-position.
These compounds may also be metabolically blocked in the 3- and/or 24-positions, in addition to the 25-position, with either a halo or O-C.
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1-5 alkyl carbamate group.
The presence of one or more of the groups listed above retards metabolic hydroxylation in vivo in the blocked position(s).
These novel metabolically blocked compounds promote intestinal-calcium transport as opposed to bone-calcium mobilization.
The novel metabolically-blocked cholecalciferol and dihydrotachysterol.
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3 compounds of this invention have the following structural formulae: ##STR1## wherein: R.
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1, is hydrogen, hydroxy, C.
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1-5 alkanoyloxy, such as acetoxy or propionyloxy, substituted C.
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1-5 alkanoyloxy, such as haloC.
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1-5 alkanoyloxy (bromoacetoxy) or branchedC.
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3-5 alkanoyloxy (isopropionyloxy), benzoyloxy or substituted benzoyloxy, such as p-nitrobenzoyloxy, R.
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3, r.
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24 and R.
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25 are hydrogen, hydroxy, C.
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1-5 alkanoyloxy, such as acetoxy or propionyloxy, substituted C.
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1-5 alkanoyloxy, such as haloC.
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1-5 alkanoyloxy (bromoacetoxy) or branchedC.
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3-5 alkanoyloxy (isopropionyloxy), benzoyloxy, substituted benzoyloxy, such as p-nitrobenzoyloxy, halo, such as chloro, bromo, iodo and especially fluoro or O--C.
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1-5 alkyl carbamate, such as O-methyl carbamate, O-ethyl carbamate or O-isopropyl carbamate with the proviso that R.
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25 must be halo or O--C.
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1-5 alkyl carbamate.
O--C.
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1-5 Alkyl carbamates have the following structure: ##STR2## In a preferred embodiment, R.
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1, R.
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3 and R.
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24 are hydrogen or hydroxy.
In a more preferred embodiment, R.
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25 is fluoro.
The novel compounds of formula I are named as derivatives of cholecalciferol.
Cholecalciferol is also known as vitamin D.
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3, activated 7-dehydrocholesterol and 9,10-seco-5,7,10(19)-cholestatrien-3