Synthesis of (25S)-[26-2H1]cholesterol and 1H N.m.r. signal assignments of the pro-R and pro-S methyl groups at C-25
- 1 January 1986
- journal article
- research article
- Published by Royal Society of Chemistry (RSC) in Journal of the Chemical Society, Perkin Transactions 1
- No. 3,p. 411-414
- https://doi.org/10.1039/p19860000411
Abstract
(25S)-[26-2H1] Cholesterol (11) has been prepared from diosgenin (1), and the absolute configuration at C-25 of the crucial intermediate, (25R)-26-hydroxycholesterol (6), has been identified by X-ray crystallographic analysis. The two methyl groups at C-25 of cholesterol have been examined by 1H n.m.r. spectroscopy and the two sets of doublet methyl signals due to 27-H and 26-H have been observed at δH 0.862 and 0.866 downfield from the internal reference. The former was assigned to 27-H, the pro-R methyl group attached at C-25, and the latter to 26-H, the pro-S methyl group attached at C-25. The 13C n.m.r. signal assignments of the methyl groups at C-25 reported by Popjak were confirmed on the basis of the signals of the deuteriated cholesterol (11).This publication has 5 references indexed in Scilit:
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