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Updated: May 2, 2026

Cellular Lipid Extraction for Targeted Stable Isotope Dilution Liquid Chromatography-Mass Spectrometry Analysis
Published on: November 17, 2011
D-homoannulation of 17alpha,21-dihydroxy-20-keto steroids (corticosteroids)
Angelo Liguori1, Francesca Perri, Carlo Siciliano
1Dipartimento di Scienze Farmaceutiche, Università degli Studi della Calabria, Via P. Bucci cubo 15/c, I-87036 Arcavacata di Rende, CS, Italy. A.Liguori@unical.it
Abstract:
Synthetic corticosteroids are widely used as anti-inflammatory agents. Mechanisms of their degradation continue to be studied. D-ring homoannulation is a well-known metabolic pathway for steroids in vivo. The rearrangement with aluminium trichloride of the commercial anti-inflammatory drugs hydrocortisone, cortisone and dexamethasone is here presented. The structures of the corresponding 17a-keto-17-hydroxy-D-homosteroids are established by mono- and two-dimensional NMR analysis. Inversion of the alpha-configuration of C-16 is observed in the Lewis acid assisted D-homoannulation of dexamethasone.
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