ISSN:
0021-8383
Keywords:
Chemistry
;
Organic Chemistry
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
Steroids. 66. 1H-N.M.R.-Investigations. Configurational Assignment of 15, 16, 17-Trisubstituted SteroidsThe 1H-n.m.r.-spectra of 15, 16, 17-trisubstituted estra-1,3,5(10)-trienes are discussed in view of the configurational assignment of the substituents. A reliable elucidation of their stereo-chemistry is possible on the basis of the coupling constants J16H,17H, J15H,16H and J14αH,15H. Additional parameters are the chemical shifts of the 15-, 16-, 17- and 18-protons (13β-methyl group) and the downfield shift of carbinol proton signals, caused by the reaction of hydroxyl groups with trichloroacetyl isocyanate. The chemical shifts of the 13β-methyl group can be calculated for compounds with trans configuration from substituent increments and for the other compounds by comparison with the chemical shifts of 16, 17-disubstituted compounds. The influence of different 16α-substituents on the chemical shifts of 15α- and 17α-protons is investigated. The downfield shifts of 15- and 17-proton signals due to the addition of trichloroacetyl isocyanate to 15, 17-diols depend on the configuration of the 16-substituents.
Additional Material:
1 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/prac.19813230205
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