| 摘要 |
<p>NEW MATERIAL:A compound expressed by formula I [R1-R3 are H or OH; R4 is H or (OH-substituted) 4-6C lower alkyl]. EXAMPLE:20alpha-(3-Methylbutyloxy)-9,10-seco-5,7,10(19)-pregnatri-en-e -1alpha,3beta-diol. USE:An antiallergic agent, antirheumatic agent and antitumor agent. PREPARATION:For example, an ether derivative expressed by formula II (R' is the same as R4 except H; R5 is triethylsilyl, tert-butyldimethylsilyl, etc.) is obtained from pregnenolone by the well-known method, and the protecting group of the hydroxyl group at the 3beta-position is converted into an acyl group. The 7-position is then subjected to bromination and dehydrobromination to form a double bond in the 7-position and give a provitamin D derivative, which is then irradiated with ultraviolet light and isomerized while heating by the conventional method to afford the aimed compound expressed by formula I.</p> |
