Proton and carbon-13 nuclear magnetic resonance spectroscopy of diastereoisomeric 3- and 17β-tetrahydropyranyl ether derivatives of estrone and estradiol

• Published in: Steroids Vol. 55; no. 5; pp. 209 - 221
• Main Authors: Boucheau, Vincent, Renaud, Mélanie, de Ravel, Marc Rolland, Mappus, Elisabeth, Cuilleron, Claude Y.
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01.05.1990
• Subjects: 13C nuclear magnetic resonance; 1H nuclear magnetic resonance; Carbon Isotopes; Cold Temperature; estradiol; Estradiol - analogs & derivatives; estrone; Estrone - analogs & derivatives; Ethers; Magnetic Resonance Spectroscopy; Protons; Stereoisomerism; steroids; tetrahydropyranyl ether diastereoisomers; estrone; steroids; 13C nuclear magnetic resonance; 1H nuclear magnetic resonance; estradiol; tetrahydropyranyl ether diastereoisomers
• ISSN: 0039-128X; 1878-5867
• DOI: 10.1016/0039-128X(90)90018-7

Protection of 3- and 17β-hydroxyl groups of estrone and estradiol as tetrahydropyranyl ether derivatives led to mixtures of 2'(R)- and 2'(S)-diastereoisomers which were separated by crystallization (3-tetrahydropyranyl ethers), or by thin-layer chromatography (17-tetrahydropyranyl ethers), and characterized by 1H and 13C nuclear magnetic resonance (NMR). Assignments for NMR signals of estradiol 3,17β-ditetrahydropyranyl ether were facilitated by comparison with those of its 15ξ,16ξ-dideuterio analog and by 2D 1H- 13C heteroshift correlation experiments. Diastereoisomers of 3-tetrahydropyranyl ether derivatives could be identified through the 13C NMR doublet signals of the anomeric C-2' and the aromatic C-4 carbon atoms in cdcl 3 . Diastereoisomers of 17-tetrahydropyranyl ether derivatives were recognized from characteristic modifications of 1H NMR signals of H-2', H-6', H-1, H-17, and 18-CH 3 protons as well as from the 13C NMR doublet signals corresponding to C-2', C-4', C-6', C-12, C-13, C-16, and C-17 carbon atoms. Low-temperature experiments showed a splitting of the C-2', C-6', and C-17 13C NMR signals of each of the two 17-tetrahydropyranyl ether isomers. The downfield signal (equatorial conformer) of the three resulting doublets was more intense for the 17-tetrahydropyranyl ether 2'(S)-isomer, whereas the upfield signal (axial conformer) was more intense for the 2'(R)-isomer. (Steroids 55:209–221, 1990).