The 220 MHz 'H spectra of isoverbanone, nopinone and verbanone are reported. The spectra of the first two are completely assigned but that of verbanone only partially. The coupling constants obtained provide information about the conformation of these molecules. The isoverbanone molecule is almost Y
The NMR spectra and conformations of cyclic compounds—VII: The conformations of β-pinene, pinocarvone and the cis- and trans-pinocarveols
✍ Scribed by R. J. Abraham; M. A. Cooper; H. Indyk; T. M. Siverns; D. Whittaker
- Publisher
- John Wiley and Sons
- Year
- 1973
- Tongue
- English
- Weight
- 466 KB
- Volume
- 5
- Category
- Article
- ISSN
- 0749-1581
No coin nor oath required. For personal study only.
✦ Synopsis
Abstract
The proton magnetic resonance spectra of β‐pinene pinocarvone and the cis‐ and trans‐pinocarveols have been completely assigned at 220 and 300 MHz. On the basis of the proton‐proton spin‐spin couplings derived, conformations have been deduced for these molecules with greater certainty than has hitherto been possible. Pinocarvone is Y‐shaped, while in all the other compounds the conformation is intermediate between a Y‐shape and a bridged chair, with the C~3~ atom bent away from the gem dimethyl groups. These conformations are discussed in terms of the steric interactions in these systems and are compared with related molecules.
📜 SIMILAR VOLUMES
## Abstract The 220 MHz PMR spectrum of car‐3‐ene (3,7,7‐trimethylbicyclo[4,1,0]hept‐3‐ene) is interpreted and a conformation deduced. In contrast to previous work, which has discussed a highly buckled structure for the 6 membered ring, the present work finds this ring to be essentially planar.
## Abstract The ^1^H magnetic resonance spectrum of the title compound has been completely analysed, using 60, 100 and 220 MHz spectrometers. The values of the chemical shifts and coupling constants obtained confirm the proposed structure and also provide information on the conformation. The molecu
## Abstract The conformations of __cis__‐ (**1**) and __trans__‐cyclopentane‐1,3‐diol (**2**) have been studied by __ab initio__ (Gaussian 98) and molecular mechanics (PCMODEL) calculations and by NMR spectroscopy. The calculations gave two low‐energy conformations for (**1**), **1A** and **1B**, b
## Abstract On the basis of NMR spectra of __trans__‐ and __cis__‐2‐alkoxy‐5,6‐α‐pyran‐6‐carboxylic esters it was found that, at room temperature, the __trans__‐compounds exist exclusively in the conformation with equatorial carbalkoxy and pseudoaxial alkoxy groups. The __cis__‐isomers appear to be
## Abstract We describe the reassignment of ^13^C NMR signals of goyazensolide based upon 1D and 2D techniques, and discuss its conformation and stereochemistry as obtained from the analysis of its proton spin–spin coupling constants, NOE measurements and molecular mechanics calculations using MM3\