13C NMR Assignments of D:C-Friedours-7-ene Derivatives. Evidence of an Abnormal Methyl Group Chemical Shift

✍ Scribed by Carlos M. Cerda-García-Rojas; Héctor H. Hernández-Vidal; Pedro Joseph-Nathan

• Publisher: John Wiley and Sons
• Year: 1996
• Tongue: English
• Weight: 420 KB
• Volume: 34
• Category: Article
• ISSN: 0749-1581
• DOI: 10.1002/(sici)1097-458x(199610)34:10<777::aid-omr967>3.0.co;2-0

✦ Synopsis

The I3C NMR assignments of four I):C-fnedours-7-ene derivatives were carried out OR the basis of 2D shiftcorrelated NMR techniques (HETCOR and FLOCK), revealing that the signal for CH,-28 appears always very deshielded (cu. S = 38.0). The conformation of the triterpene skeleton, obtained by MMX calculations, is compared with that of multiflor-'l-ene.