Fluorination of steroid estrogens with Selectfluor®: Elucidation of regio- and stereoselectivity

• Published in: Journal of fluorine chemistry 2014-12, Vol.168, p.218-222
• Main Authors: Bogautdinov, Roman P., Fidarov, Alan F., Morozkina, Svetlana N., Zolotarev, Andrei A., Starova, Galina L., Selivanov, Stanislav I., Shavva, Alexander G.
• Format: Article
• Language: English
• Subjects: 10-Fluorosteroids; 8α-Estradiol; NMR spectroscopy methods; Selectfluor; Stereoselectivity of fluorination
• ISSN: 0022-1139; 1873-3328
• DOI: 10.1016/j.jfluchem.2014.09.030

Two steroid estrogens, natural estradiol and 8α-estradiol, were fluorinated using Selectfluor® in ionic liquid. Unexpectedly, mostly products of fluorination at position C-10 were isolated. The reaction proceeds stereoselectively, yielding different stereoisomers for different types of the steroid skeleton. •Reaction of estradiol and 8α-estradiol with Selectfluor® was perfomed.•Mostly the product of fluorination at C-10 was isolated.•Results for estradiol are completely different from those reported in literature.•The fluorination occurs stereoselectively. Two steroid estrogens, natural estradiol and 8α-estradiol, were fluorinated using Selectfluor® in ionic liquid. Unexpectedly, mostly products of fluorination at position C-10 were isolated instead of corresponding fluorophenols, as it was reported previously. The reaction proceeds stereoselectively, yielding different stereoisomers for different types of the steroid skeleton. Stereoselectivity was proved by 1D/2D NMR experiments and X-ray analysis of obtained products. The obtained compounds are suitable intermediates for synthesis of various classes of estrogens.