H-1 AND C-13 NUCLEAR-MAGNETIC-RESONANCE ASSIGNMENTS AND STEREOCHEMISTRY OF N-N-BUTYL-N-METHYL-11-(16'ALPHA-CHLORO-3',17'BETA-YL AND 17'ALPHA-DIHYDROXYESTRA-1',3',5'(10')-TRIEN-7'ALPHA-YL) UNDECANAMIDE

The stereochemistry of N-n-butyl-N-methyl-11-(16'alpha-chloro-3',17'beta-dihydroxyestra-1',3',5'(10')-trien-7'alpha-yl) undecanamide (4) and N-n-butyl-N-methyl-11-(16'alpha-chloro-3',17'alpha-dihydroxyestra-1',3',5'(10')-trien-7'alpha-yl) undecanamide (5) at the 17'-position was unambiguously established by one dimensional nuclear Overhauser enhancement (NOE difference spectroscopy). Irradiation of H-18' led to the increase in the signal of H-11'beta, H-12'beta, H-8'beta, H-15'beta, and H-16'beta for compound 4 and a very small increase in the signal of H-17' indicating the beta-orientation of the 17'-OH. In contrast, for compound 5, the increase in the signal of H-17' indicated the alpha-orientation of the 17'-hydroxy group. Complete assignment of the H-1 and C-13 resonances is facilitated by the following one- and two-dimensional NMR experiments. H-1 homonuclear correlated spectroscopy (COSY), H-1-C-13 heteronuclear shift correlation (HSC), H-1-C-13 heteronuclear shift correlation via long range couplings (COLOC), and distortionless enhancement by polarisation transfer (DEPT). Comparison of the H-1 and C-13 NMR chemical shifts indicates that the stereochemistry at the 17' position is more easy to determine by analysing the chemical shifts of C-17', C-12', and C-18'.