Steroids with hydroxyl group in positions 2, 3, 6, 7, 17 and 20 were esterified with heptafluorobutyric anhydride. The obtained esters on treatment with lithium bromide in N,N-dimethylacetamide in the presence of pyridinium tosylate afforded the corresponding olefins in high yields.
在2、3、6、7、17和20位上带有羟基的类固醇被七氟丁酸酐酯化。在N,N-二甲基乙酰胺中,经过溴化锂处理,在对甲苯磺酸吡啶存在下,得到的酯以高产率生成相应的烯烃。