Process for the preparation of 1alpha, 25-dihydroxycholecalciferol, a compound with improved antirachitic properties compared to vitamin D2, and D3, and which has value as a ADDING substance for impregnation agents, and relates to intermediates for their preparation

摘要

1496319 Cholesta-5,7-diene derivative WISCONSIN ALUMNI RESEARCH FOUNDATION 27 Feb 1976 [28 Feb 1975] 06294/77 Divided out of 1496317 Heading C2U The invention comprises cholesta-5,7-diene- 1,3#,25 - triol (I) and its preparation from cholesta - 1,5,7 - triene - 3#,25 - diol (VII) by reaction with a 4-substituted-1,2,4-triazoline- 3,5-dione to give V infra, epoxidation of which gives IV infra, reduction of which with a metal hydride (e.g. LiAlH 4 or LiBH 4 ) yields I (R is alkyl, aryl or monosubstituted aryl). IV may be accompanied by 1#,2#-epoxy epimer which is separated chromatographically. Conversion of I to 1,25-dihydroxycholecalciferol is as described in parent Specification. Compound VII and precursors thereof are the subject of Specification 1,496,318.