| Popis: |
C26 Bile of the 24-nor-5β-cholestane series were prepared starting from methyl cholate. A Grignard reaction of methyl magnesium iodide with methyl cholate yielded 24-nor-5β-cholestane-3α,7α,12α,25-tetrol which was dehydrated to form a mixture of 24-nor-5β-cholest-23-ene-3α,7α,12α-triol and the corresponding Δ25 compound. Oxidation of the former with OsO4 yielded 24-nor-5β-cholestane-3α,7α,12α,23ξ,25-pentol, while catalytic hydrogenation of a mixture of the Δ23 and Δ25 triols resulted in the formation of 24-nor-5β-cholestane-3-α,7α,-12α-triol. The structures of these new compounds were confirmed by infrared and nuclear megnetic resonance spectrometry and by gas–liquid chromatography–mass spectrometry. |
