Difluoroboron Complexes as Versatile Precursors for Steroid Modification. Lumiestrone-Based Steroid Derivatives:
Anna A Sukhanova1, Mikhail A Prezent1, Mikhail E Minyaev1,2
1N. D. Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences, 47 Leninsky Prosp., 119991, Moscow, Russian Federation.
Abstract:
A preparation method for steroid-based difluoroboron complexes has been developed using lumiestrone as a steroid example. Previously inaccessible lumiestrone-based difluoroboron complexes annulated at positions 16 and 17 of the D ring have been prepared. Such difluoroboron complexes may have large synthetic potential for heterofunctionalization of steroids at the D ring. An application of a borylation mixture Ac2O-BF3⋅OEt2 significantly simplify the preparation of steroid "dimers" bearing two estrone moieties connected at positions 2 and 2' via a linker. Crystal structures of key representatives have been determined by X-ray diffraction.
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