Hoxan Corporation

Yuji Tahara

There are disclosed novel compounds that can be used to derive therefrom a fragment that corresponds to an A-ring which is to he combined with fragments which respectively correspond to C- and D-rings in synthetic formation of vitamin D.sub.3 derivatives by cleaving the 7,8-bondings by means of oxidizing agents following any known process. According to the invention, there is provided an industrially efficient and effective method of manufacturing above compounds that utilizes allylic hydroxylation to add an oxygen function group to position C(1), a method which is completely different from any existing synthetic methods.

1-.beta.7,8-trihydroxy vitamin D.sub.2, 1.beta.7,8-trihydroxy vitamin D.sub

There are disclosed novel compounds that can be used to derive therefrom a fragment that corresponds to an A-ring which is to be comined with fragments which respectively correspond to C- and D-rings in synthetic formation of vitamin D.sub.3 derivatives by cleaving the 7,8-bondings by means of oxidizing agents following any known process. According to the invention, there is provided an industrially efficient and effective method of manufacturing above compounds that utilizes chemical reaction of allylic acid to add an oxygen function group to position C(1), a method which is completely different from any existing synthetic methods.

1.beta.,7,8-trihydroxy vitamin D.sub.2, 1.smallcircle.,7,8-trihydroxy

There is provided a method with which vitamin D.sub.2, vitamin D.sub.3, activated type vitamin D.sub.2, activated type vitamin D.sub.3 and their derivatives are prepared from 7,8 -dihyroxy vitamin D.sub.2, D.sub.3 or any of their derivatives by means of a reducing elimination technique involving as cyclic orthoester of a 7,8-dihydroxy compound or a thiocarbonate compound as an intermediate compound or an elimination technique utilizing a reducing metal such as titanium. The method according to the invention ensures a practical and simple synthetic process and a high yeild as compared with any existing methods for manufacturing these chemicals.

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Sapporo, Japan

Yuji Tahara