Process for precursors to calcitriol and related compounds
AssigneeHoffmann-La Roche Inc.
InventorsGeorge P. Yiannikouros, Percy S. Manchand
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Abstract
The process of the invention comprises reacting a C-22-halo-23,24-bisnorsteroid or C-22-halo-23,24-bisnor-9,10-secosteroid with a nickel complex of an electron withdrawing alkene of the formula ##STR1## wherein R.sub.1 is hydrogen, hydroxycarbonyl, lower alkoxycarbonyl, lower alkylcarbonyl or unsubstituted or substituted lower alkyl, and R.sub.2 is hydroxyl, lower alkoxy, or unsubstituted or substituted lower alkyl, to yield a C-25 or C-26 precursor of the formula ##STR2## which is appropriately functionalized for conversion into the corresponding steroid or secosteroid by treatment as hereinafter described.
Claims6
A process for the preparation of a compound of the formula ##STR14## wherein A is a 23,24-bisnorsteroid or a 23,24-bisnor-9,10-secosteroid radical, R.sub.1 is hydrogen, hydroxycarbonyl, lower alkoxycarbonyl, lower alkylcarbonyl or unsubstituted or substituted lower alkyl, and R.sub.2 is hydroxyl, lower alkoxy, or unsubstituted or substituted lower alkyl,
- (1) which comprises reacting a compound of the formula ##STR15## with a nickel salt hydrate or, if unhydrated, in the presence of a proton source and a reducing agent;
- in the presence of an organic solvent and ligand source, and thereafter,
- (2) treating the reaction product of step 1, with a compound of the formula
- AX II
- wherein A is as previously described, and X is halogen to yield the corresponding compound of formula IV.
Dependencies are inferred from the claim text.