ISSN:
1573-9171
Source:
Springer Online Journal Archives 1860-2000
Topics:
Chemistry and Pharmacology
Notes:
Conclusions 1. An analysis was made of the high-resolution13C NMR spectra of nine new 20-ketoteroids modified in ring D with an additional cyclobutane, cyclobutene, cyclohexane, or cyclohexene ring D' at positions 16,17. 2. On the basis of the NOE coefficients the orientations of rings D' in relation to the steroid skeleton were determined. In the case of the cyclobutene ring D' it was shown that δC14 and δC12 are characteristic of the α,α and β,β orientations of ring D'. 3. During analysis of the mutual effects of ring D' and the steroid skeleton on their δ13C values an abnormally large descreening effect was found from the cyclobutene ring in the β,β orientation on δC14.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00957537