Application of relayed coherence transfer two-dimensional nuclear magnetic resonance spectroscopy to the assignment of 1H chemical shifts in steroids

✍ Scribed by Donald W. Hughes

• Publisher: John Wiley and Sons
• Year: 1988
• Tongue: English
• Weight: 813 KB
• Volume: 26
• Category: Article
• ISSN: 0749-1581
• DOI: 10.1002/mrc.1260260308

✦ Synopsis

Relayed coherence transfer (RELAY) two-dimensional NMR spectroscopy was demonstrated to be an effective technique for overcoming the problem of overlapping multiplets in the analysis of the 'H NMR spectra of steroids. Cross-sections through appropriate proton resonances resulted in resolved spectra of the spin systems for each of the saturated rings of the estrogenic hormones 178-and 17a-estradiol. During RELAY experiments with a fixed delay time of 0.042 s it was possible to observe RELAY cross-peaks between H-lla and 18-CH3 which resulted from magnetization transfer via long-range coupling between 1&CH3 and H-12a. The difference in stereochemistry at C-17 of these estradiol epimers allowed an examination of the effect of substituent configuration on the RELAY cross-peak intensity in order to determine the ability of the RELAY method to provide qualitative structural information.