| 摘要 |
<p>The admixture of coke-oven gas with the conventional hydrogen in the prepn. of palladium-charcoal catalyst permits the selective and stereospecific dehalogenation and hydrogenation at improved yields of steroids and other cpds. carrying halogen and/or methylene groups without affecting the double-bonds. In an example, (A) a catalyst contg. 5% Pd is obtd. from a hot aqs. soln. of 5 g. PdCl2 stirred at 50 degrees with 54 g. active charcoal in 100 ml. H2O and treated with a current of 96% H2 and 4% coke-oven gas, and (B) 96% pure 16 beta-methyl-17 alpha-hydroxy-1,4,9(11)-pregnatriene-3,20-dione is obtd. from 85 g. of the corresp. 6-chloro-16-methylene deriv. in 900 ml. AcOH hydrogenated at 20-30 degrees in presence of 12 g. C/Pd catalyst.</p> |
