DRY OZONATION OF STEROIDS - C-25 FUNCTIONALIZATION OF CHOLESTANE DERIVATIVES

The ozonation of substrates adsorbed on dry silica gel is a convenient method to introduce oxygen into unactivated tertiary C-H bonds. This method involves preadsorption of substrate on chromatographic grade silica gel and passing over it ozone at temperatures between -75 and -45 °C, followed by elution with an appropriate solvent. The reactivity of C-H bonds toward ozone depends both on the electronegativity of the C atom and on its steric availability. © 1979, American Chemical Society. All rights reserved.