Process for 1.alpha.,3.beta.-dihydroxy-.DELTA..sup.5 -steroids
AssigneeHoffmann-La Roche Inc.
InventorsAndor Furst, Ludwig Labler, Werner Meier
Life of this patent
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Abstract
A process for the synthesis of 1.alpha.,3.beta.-dihydroxy-.DELTA..sup.5 -steroids from steroids such as 1.alpha.,2.alpha.-epoxy-cholesta-4,6-dien-3-one, which is reacted with lithium in liquid ammonia in the absence of a proton donator and subsequently reduced by repeated alternative additions of a proton donator, said additions being followed in each case by an equivalent amount of lithium. The final product, a 1.alpha.,3.beta.-dihydorxy-.DELTA..sup.5 -steroid, is useful in the synthesis of derivatives of cholecalciferol.
Claims20
A process for the preparation of 1.alpha.,3.beta.-dihydroxy-.DELTA..sup.5 -steriods of the partial formula (I):
- ##STR11## which process comprises the steps of:
- (A) reducing a steriod of the partial formula (II):
- ##STR12## in a solvent with at least a stoichiometric amount of lithium in liquid ammonia in the absence of a portion donator, producing thereby a steroid of the partial formula (III):
- ##STR13## (B) reacting the steroid of partial formula III with an amount of a proton donator, which amount is substantially equivalent stoichiometrically to the amount of lithium utilized in step A, producing thereby a steroid of the partial formula (IV):
- ##STR14## and (C) reducing the steroid of partial formula IV by repeated alternating addition of a proton donator with the addition of lithium, each addition of the proton donator being followed by the addition of lithium in an amount substantially equivalent stoichiometrically to the amount of added proton donator, producing thereby the steriod of partial formula (I).
A process for the preparation of steriods of the partial formula (III):
- ##STR18## which process comprises reducing a steriod of the partial formula (II):
- ##STR19## in a solvent with at least a stoichiometric amount of lithium in liquid ammonia in the absence of a proton donator, producing thereby a steriod of the partial formula (III).
A process for the preparation of 1.alpha.,3.beta.-dihydroxy-.DELTA..sup.5 -steroids of the partial formula (I):
- ##STR20## which process comprises reacting a steroid of the partial formula (III):
- ##STR21## with an amount of a proton donator, which amount is substantially equivalent, stoichiometrically to the amount of lithium present in said steroid of the partial formula III, producing thereby a steroid of the partial formula (IV):
- ##STR22## and then reducing the steroid of partial formula IV by repeated alternating addition of a proton donator with the addition of lithium, each addition of the proton donator being followed by the addition of lithium in an amount substantially equivalent stoichiometrically to the amount of added proton donator, producing thereby the steroid of partial formula (I).
Dependencies are inferred from the claim text.