13C NMR spectroscopy of the withanolides and other highly oxygenated C28 steroids
- 1 May 1981
- journal article
- research article
- Published by Wiley in Magnetic Resonance in Chemistry
- Vol. 16 (1) , 20-25
- https://doi.org/10.1002/mrc.1270160107
Abstract
The 13C NMR spectra of 29 highly oxygenated C, steroids with the withanolide skeleton, 24 of which are naturally occurring substances or acetates thereof, were recorded and the carbon signals fully assigned. The shifts of the heavily functionalized A/B ring system can serve as a ‘fingerprint’ for the different substitution patterns. A study of the effects of hydroxyl substitution in the ring D/side chain part of the molecules leads to conformational information, including preferred rotamers around the 17—20 and 20—22 bonds. Systems with both 17α‐ and 17β‐oriented side chains are thus analysed.Keywords
This publication has 7 references indexed in Scilit:
- Carbon-13 Nuclear Magnetic Resonance Spectral Analysis of Naturally occurring Withanolides and Their DerivativesJournal of Natural Products, 1979
- Convenient method for the synthesis of 25-hydroxyvitamin D3 analog. Structure determination of tertiary alcohols by carbon-13 nuclear magnetic resonance spectroscopyThe Journal of Organic Chemistry, 1979
- 13C n.m.r. spectra of steroids —a survey and commentaryMagnetic Resonance in Chemistry, 1977
- Long range substituent effects relfected in the 13C NMR spectra of allyl alcohols and their derivativesMagnetic Resonance in Chemistry, 1975
- Structure of Nic-2, a major steroidal constituent of the insect repellent plant Nicandra physaloidesJournal of the Chemical Society, Chemical Communications, 1974
- Nicandrenone, an insecticidal plant steroid derivative with ring D aromaticJournal of the American Chemical Society, 1972
- Crystal and molecular structure of withanolide E, a new natural steroidal lactone with a 17α-side-chainJournal of the Chemical Society, Chemical Communications, 1972