猪去氧胆酸化学——8.锇催化不对称双羟化合成(24R,25R)-24,25,26-三羟基胆固醇

Chemistry of Hyodeoxycholic Acid——8. Stereoselective Synthesis of (24R, 25R) -24, 25,26-Trihydroxycholesterol by Using Osmium-Catalyzed Asymmetric Dihydroxylation of Olefine

本文报道应用锇催化不对称双羟化对甾体化合物侧链三取代双键的反应合成得光学纯3a和3b,(3a∶3b=6.5:1),收率分别为71％和11％.从3a经五步反应合成新的维生素D_3类似物的关键中间体(24R,25R)-243 25,26-三羟基胆固醇(10).

This paper reports a stereoselective synthesis of (24R, 25R)-24, 25, 26-trihydroxycholesterol 10, which is important intermediate for synthesis of Vitamin D_3 analog, through seven steps from 1. The key step is Osmium-Catalyzed asymmetric dihydroxylation of compound 2. The total yield is 40%.