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procedure for the manufacture of vitamin d2, vitamin d3, activated type vitamin d2, activated type vitamin d3 and their derivatives
procedure for the manufacture of vitamin d2, vitamin d3, activated type vitamin d2, activated type vitamin d3 and their derivatives
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机译:维生素d2,维生素d3,活化型维生素d2,活化型维生素d3及其衍生物的生产程序
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摘要
PURPOSE:To practically obtain vitamin Ds through simplified processes in high yield by reductive elimination reaction of 7,8-dihydroxyvitamin D2 through a cyclic orthoester in the 7,8-dihydroxy groups. CONSTITUTION:A compound of formula I (R is H, dotted line is C-C bond, R is methyl, dotted line represents additional bond (for example double bond; R1-R3 are H, hydroxyl protecting group; X, Y are H, hydroxyl and its derivative) is subjected to reductive elimination reaction passing through 7,8-dihydroxy cyclic orthoester or its homologue and thionocarbonate, or elimination reaction of the 7,8-dihydroxy derivative with a metal such as reduced titanium to produce vitamin D2 and D3 or active form of vitamim D2, D3 or their derivatives.
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