| 摘要 |
<p>PURPOSE:To provide an effective process for producing an active vitamin D3 having excellent differentiation-inducing activity and bone mass-improving activity. CONSTITUTION:A cyclovitamin D3 derivative of formula I is subjected to a protection treatment at 25-hydroxyl group to obtain a compound of formula II, e.g. 25-hydroxy-3,5-cyclovitamin D3 25-triethylsilyl ether and then to selective hydroxylation of 1alpha-position. The product of formula III is treated with acetic acid to obtain a compound of formula IV (Ac is acetyl), e.g. 1alpha, 25- dihydroxyvitamin D3 3beta-acetate 25-triethylsilyl ether. Subsequently, the protecting group of the 25-hydroxyl. group of a compound of formula IV is removed to lead to a compound of formula V. Then, the compound is subjected to hydrolysis to remove 3beta-acetyl group to obtain 1alpha, 25-dihydroxyvitamin D3 of formula VI. The compounds of formula II to formula IV obtained in these processes are unknown compounds. The compound of formula I as a starting material is synthesized through tosylation of 25-hydroxyvitamin D3 followed by methanolysis.</p> |
