3β,5α,6β-Trihy-droxy-androstan-17-one

Crystal structures and Hirshfeld surface analyses of the hemi-hydrate and hemi-methanolate of 3α-hydroxy-16α-bromoandrostan-17-one, 3: Differences in supramolecular arrangements

The crystal structures and Hirshfeld surface analyses of two hemi-solvates of 3α-hydroxy-16α-bromoandrostan-17-one, 3, namely [(3)₂.(H₂O)] and [(3)₂.(MeOH)], are reported. Both solvates crystallize in the monoclinic space group, P2₁, with Z = 4._. The asymmetric unit of the hemi-hydrate [(3)₂.(H₂O)] contains two independent but similar steroid molecules and a water molecule, while that of the hemi-methanoate [(3)₂.(MeOH)] has four similar but independent steroid molecules and two methanol molecules. Very similar conformations are found for the steroid molecules in both solvates. In both solvates, the strongest intermolecular interactions are OH···O hydrogen bonds, involving hydroxyl groups of the steroid and the solvate molecule, which result in head-to-head directly linked steroid molecules and solvate separated steroid molecules. In both cases, the oxygen atoms of the carbonyl groups of the steroids are involved in weaker CH···O hydrogen bonds which directly link steroid molecules in tail-to-tail fashions. Combinations of the hydrogen bonds, both OH···O and CH···O, result in two-molecule wide sheets in the hemi-hydrate, which are further weakly linked in the hemi--methanoate into a 3-dimensional array. Very different hydrogen bonded chains are found in the two solvates. There is a higher proportion of CH···O to OH···O hydrogen bonds in the hemi-methanoate, [8-6], compared to that in the hemi-hydrate [1-4]: this is an indication of the weaker solvating influence of methanol compared to water.

Unusual hydrogen bond patterns contributing to supramolecular assembly: conformational study, Hirshfeld surface analysis and density functional calculations of a new steroid derivative

Structural and conformational study of a new steroid derivative using X-ray and density functional calculations.

Androstane-3β,5α,6β,17β-tetrol tri-hydrate

The title hydrated tetrol, C(19)H(32)O(4)·3H(2)O, was synthesized by stereoselective reduction of the compound 3β,5α,6β-trihy-droxy-androstan-17-one. All rings are fused trans. The organic mol-ecules are connected head-to-tail along the c axis via O-H⋯O hydrogen bonds. Layers of water mol-ecules in the ab plane inter-connect these chains. A quantum chemical ab initio Roothan Hartree-Fock calculation of the isolated mol-ecule gives values for the mol-ecular geometry close to experimentally determined ones, apart from the C-O bond lengths, whose calculated values are significantly smaller than the measured ones, probably a consequence of the involvement of the C-OH groups in the hydrogen-bonding network.