Derivatives of 16α-hydroxy-dehydroepiandrosterone with an additional 7-oxo or 7-hydroxy substituent: Synthesis and gas chromatography/mass spectrometry analysis

Derivatives of 16α-hydroxy-dehydroepiandrosterone, which have an additional oxygen substituent at position 7 (oxo or hydroxy group), were synthesized. Firstly, 17,17-dimethoxyandrost-5-ene-3β,16α-diyl diacetate was prepared and then oxidized with a complex of chromium(VI) oxide and 2,5-dimethylpyrazole to the respective 7-oxo derivative. This key intermediate was both deprotected or reduced by l-Selectride® or sodium borohydride in the presence of cerium(III) chloride and then deprotected to give 7-oxo, 7α-hydroxy and 7β-hydroxy derivatives of 16α-hydroxy-dehydroepiandrosterone. The target compounds were characterized by 1H and 13C NMR spectra and in the form of O-methyloxime-trimethylsilyl derivatives, by gas chromatography/mass spectrometry methods.