Abstract

GARCIA, Cirilo; TAPIA, Josefina  and  CERVANTES, Humberto. Improved Synthesis of (20S)-3β-Acetoxy-23,24-dinorchol-5-en-22-aldehyde. Rev. Soc. Quím. Méx [online]. 2002, vol.46, n.1, pp.49-53. ISSN 0583-7693.

Commercial 3β-acetoxy-23,24-dinorchol-5-en-22-oic acid was transformed into (20S)-3β-acetoxy-23,24-dinorchol-5-en-22-aldehyde in a two-step process. The key step was reduction of the imidazolide derived from the above mentioned acid, which invariably produced the target aldehyde and 22-hydroxy-23,24-dinorchol-5-en-3β-yl acetate. In adittion to these products, the work-up of the organic material from the latter reaction, afforded pregn-5-en-3β-yl acetate along with the mixture of the former acid and its unreacted imidazolide. Oxidation of 22-hydroxy-23,24-dinorchol-5-en-3β-yl acetate with pyridinium chlorochromate and recycling of the mixture acid/imidazolide, enhances the practical value of this process. Structural analysis, based on ¹H NMR spectroscopy and polarimetry of intermediate and final products, and observations on the stability of the imidazolyl derivative and aldehyde are briefly discussed.

Keywords : Pregn-5-ene-20-carboxaldehyde; 3-acetoxy-bisnor-5-cholenaldehyde; dinorcholenic acid; bisnorcholenic acid; steroidal imidazolid.

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