𝔖 Bobbio Scriptorium
✦   LIBER   ✦

Unambiguous assignment of 13C chemical shifts of some hopane and migrated hopane derivatives by 2D NMR

✍ Scribed by Ajit K. Chakravarty; Kazuo Masuda; Hideki Suzuki; Hiroyuki Ageta

Book ID
104204309
Publisher
Elsevier Science
Year
1994
Tongue
French
Weight
696 KB
Volume
50
Category
Article
ISSN
0040-4020

No coin nor oath required. For personal study only.

✦ Synopsis

1% NMR chemical shifts of some migrated hopane derivatives, viz. boehmeryl acetate (l), neohop-13(18)-en-35-ol (2) neomotiol (3), arborinol (4), isoarborinyl acetate ( ) fernenol (6) fernenyl acetate (7) and simiarenol (6), and a hopane derivative, hop-l 7(21)-en-35yl acetate ( ) have been assigned unambiguously on the basis of detailed 20 NMR analyses. Heteronuclear Multiple Bond Correlation (HMBC) spectrum was found to be most informative not only in the assignment of signals to specific carbons but also in the elucidation of back-bone structure of triterpenoids. The relative stereochemistry of most of the chiral centres of the back-bone could also be established from the NOESY spectra.

2866

A.K. CHAKRAVARTY etal.

simiarenol (8)* and hop-l 7(21)-en-3J3-yl acetate [g)s, whose 1% NMR data are not known so far. in the process, 1H NMR signals of methyl protons in particular have also been assigned.

Assignments of lsC NMR chemical shifts for l-9 are summarized in Table and those of 1 H chemical shii particularly of methyl proton8 of l-9 are listed in Tables 2-l 0. 7 FkOAc = , 5 ,-" o

πŸ“œ SIMILAR VOLUMES

2D NMR studies on mortonin A, C and D. U
2D NMR studies on mortonin A, C and D. Unambiguous assignment of 13C chemical shifts
✍ L. RodrΓ­guez-Hahn; M. JimΓ©nez; E. DΓ­az; K. Jankowski; D. Davoust; P. Fagerness πŸ“‚ Article πŸ“… 1990 πŸ› John Wiley and Sons 🌐 English βš– 521 KB

## Abstract High‐field 2D NMR studies of mortonins were performed at 500 MHz (^1^H) and 125 MHz (^13^C). Unambiguous assignment both of the ^13^C data to the carbon skeleton and that of the proton chemical shifts in these molecules was achieved, together with the establishment of the configuration

Total Assignment of the 1H and 13C NMR C
Total Assignment of the 1H and 13C NMR Chemical Shifts of Three Bisabolane Hydrocarbons by 2D-NMR Spectroscopy
✍ Lai-King Sy; Geoffrey D. Brown πŸ“‚ Article πŸ“… 1997 πŸ› John Wiley and Sons 🌐 English βš– 151 KB πŸ‘ 2 views

Three known bisabolane hydrocarbons, a-trans -bergamotene, sesquiphellandrene and zingiberene, were isolated from the aerial parts of Alpinia densibracteata . Their 1H and 13C NMR spectra were completely assigned by using a combination of 13C DEPT and 2D-NMR experiments (1H-1H COSY, single-bond 13C-

Natural abundance one-bond 13C13C coupli
Natural abundance one-bond 13C13C coupling constants and unambiguous assignments of 13C NMR chemical shifts of dithieno[b,d]pyridines; a multivariate data analysis
✍ Salo Gronowitz; Anna-Britta HΓΆrnfeldt; Youhua Yang; Ulf Edlund; Bertil Eliasson; πŸ“‚ Article πŸ“… 1990 πŸ› John Wiley and Sons 🌐 English βš– 654 KB

## Abstract The one‐bond ^13^Cο£Ώ^13^C coupling constants (^1^__J__CC) in all nine possible dithieno[__b,d__]pyridines were measured at natural isotope abundance by using the INADEQUATE pulse sequence technique. The unambiguous assignments of the ^13^C NMR shifts of these compounds are also reported.