| 摘要 |
<p>NEW MATERIAL:A compound of formula I (R<1>-R<4> are H, OH-protecting group; A is >N-Ar<2>, 0-phenylene; X is H, acyl ; Ar<1>, Ar<2> are aryl). USE:An intermediate for synthesizing 1,25-dihydroxy vitamin D3 26,23-lactone. PREPARATION:A compound of formula II (R<11>, R<21> are H, OH-protecting group) is reacted with a compound of formula III preferably in a molar ratio of 1:0.5-20 in the presence of a basic substance such as n-butyl lithium. The reaction is preferably performed in a solvent such as diethyl ether at a temperature of -80 to 20 deg.C.</p> |
