Hydroxy Derivatives of Poststerone and Its Nontrivial 13(14→8)-Abeo-analogues: Synthesis, Crystal Packing, and Intermolecular Hydrogen Bonds

Abstract

ABSTRACT The 6,20-dioxo-Δ2,3-pregnane and 6,20,14-trioxo-13(14→8)-abeo-pregnane steroid hydroxyl derivatives are synthesized via the reduction with metal hydrides (NaBH4, LiAlH4, and L-Selecride). The structures of the derivatives were elucidated with single-crystal X-ray diffraction analysis, MALDI TOF/TOF mass spectrometry, and 1D and 2D NMR spectroscopy. The topological analysis with a QTAIM approach, the analysis of molecular electrostatic potentials mapped on a Hirshfeld surface, and the CLP-PIXEL method show unequivocally that there is a complex network of intramolecular and intermolecular interactions in the crystals of the pregnane steroids. The molecules of 20(R)-2β,3β-dimesyloxy-14α,20-dihydroxy-5β-pregn-7-en-6-one 2 form a 2D motif (network) due to strong O–H...O hydrogen bonds. The (8R)-8,13-cyclo-13,14-seco-5β-pregn-2-ene-6,14,20-trione 4 and 6α,8R-8,13-cyclo-13,14-seco-5β-pregn-2(3)-en-6-hydroxy-14,20-dione 9 provide two-dimensional network of a brick wall type in their crystals due to weak С–Н...О contacts, whereas 6α,14α,8R,20R-8,13-cyclo-13,14-seco-5β-pregn-2(3)-en-6,14,20-triol 10 forms one-dimensional network (chains) in its crystals owing to strong O–H...O intermolecular interactions. When the number of hydroxyl groups in abeo-steroid increases, the contribution of O...H contacts to the Hirshfeld surface decreases from 26 to 11%.