PURPOSE: To provide the new compounds each of which is a precursor for synthesizing a 24-homo-vitamin D3 derivative useful for treating hypoparathyroidism, osteodystrophia, etc.
CONSTITUTION: The new compounds are those represented by the formula (wherein: R is a 1-4C acyl or benzoyl group; each of R4 and R5 is H, or R4 and R5 are joined together to form a carbon-carbon double bond), such as (22E)-1d,3β-diacetoxy-25-hydroxy-24 homocholesta-5,7,22-triene. The preparation of such a compound represented by the formula I comprises: successively subjecting bis(norcholeic acid) acetate to reduction and oxidation to obtain a compound represented by the formula II; thereafter, successively subjecting the compound represented by the formula II to treatment with alkaline H2O2, reduction and treatment with chloromethyl methyl ether, to obtain a compound represented by the formula III (wherein R is a THP group); further, removing the THP group from the compound represented by the formula III; thereafter, subjecting the resulting compound to Swern oxidation; subsequently, allowing the oxidized product to react with vinylmagnesium bromide to obtain a compound represented by the formula IV; and finally, esterifying the compound represented by the formula IV to obtain an ester compound and to prepare the objective compound from the ester compound through a compound represented by the formula V (wherein R is an acetyl group).
IKEGAWA NOBUO
TANAKA YOKO
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