Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
9770092 | Journal of Molecular Structure | 2005 | 9 Pages |
Abstract
A series of compounds deriving from 12α- and 12β-hydroxytigogenin (1, 2), pseudohecogenin 6, 23-bromo derivatives of hecogenin and sarsapogenin (3-5) and products (7-9) of their transformation was analysed by 13C NMR in solution and in the solid state. The model structures containing three or four rings have been calculated by DFT B3LYP/6-31G** method. On the basis of the GIAO DFT shielding constants and experimental data the influence of 23-Br and 12-OH group configuration on chemical shifts of carbon atoms in adjacent rings was estimated. Analysis of CPMAS shifts indicated that the acetate carbonyl group at C-3 in 1a is involved in an intermolecular hydrogen bond with 12α-OH; compounds 8 and 9 exhibit polymorphism.
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Physical Sciences and Engineering
Chemistry
Organic Chemistry
Authors
Jacek W. Morzycki, Katarzyna Paradowska, Karolina DÄ
browska-Balcerzak, Izabella Jastrzebska, Leszek Siergiejczyk, Iwona Wawer,