THE STEREOCHEMISTRY OF MALEOPIMARIC ACID AND THE LONG RANGE SHIELDING EFFECT OF THE OLEFINIC BOND

Nuclear magnetic resonance studies of methyl maleopimarate and closely related derivatives clearly establish the stereochemistry of methyl maleopimarate and, consequently, levopimaric acid. An extension of this study to other related compounds, 22 in all, provides evidence, on the basis of an interc...

Full description

Saved in:
Bibliographic Details
Published in:Canadian journal of chemistry 1963-05, Vol.41 (5), p.1113-1126
Main Authors: Ayer, W. A, McDonald, C. E, Stothers, J. B
Format: Article
Language:English
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:Nuclear magnetic resonance studies of methyl maleopimarate and closely related derivatives clearly establish the stereochemistry of methyl maleopimarate and, consequently, levopimaric acid. An extension of this study to other related compounds, 22 in all, provides evidence, on the basis of an intercomparison of the chemical shifts for the angular methyl protons, to support the original suggestion by Jackman (Applications of NMR in organic chemistry. Pergamon, New York. 1959. Chap. 7) that the long range shielding effect of the olefinic linkage is analogous to that of the carbonyl double bond. Coupling constants and chemical shifts for some of the protons of the bicyclo[2.2.2]octene system present in these compounds are also discussed.
ISSN:0008-4042
1480-3291
DOI:10.1139/v63-159