| 摘要 |
In the synthesis of DELTA <1,4> 16 beta -Me- 17 alpha -acyloxy-corticoids for saturated 16 beta -Me-17 alpha -OH-5 alpha -H analogues thereof, the 11 beta -OH group is protected by trimethylsilylation during the 17-acylation and subsequent 1,4-dehydrogenation with DDQ. Specified corticoids are betamethasone 17-valerate (and its 21-acetate), betamethasone dipropionate, beclomethasone dipropionate, and clobetasol propionate. The 11-trimethylsilyloxy intermediates are claimed per se. |
