Evidence map›Paper›PMID 24354614›Full record

ArticleThe Journal of organic chemistry2014

Analysis of seven-membered lactones by computational NMR methods: proton NMR chemical shift data are more discriminating than carbon.

Daniel J Marell, Susanna J Emond, Aman Kulshrestha, Thomas R Hoye

Abstract read
In one paragraph

Article in The Journal of organic chemistry, 2014. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 8 papers.

0numbers the graph read from it
0cells of the map it votes in
8citing papers in PubMed
2.9field-weighted citation impact, top 10% of its field
1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.

Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

Who cites it

8 citing papers in PubMed, 44 citations in OpenAlex.

  1. Article
  2. Improving the accuracy ofBeilstein journal of organic chemistry · 2023
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  4. Two New Diterpenoids fromFrontiers in chemistry · 2021
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  5. Article
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4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

4 authors at 1 institution in 1 country.

Daniel J MarellDepartment of Chemistry, University of Minnesota , Minneapolis, Minnesota 55455, United States.
Susanna J Emond
Aman Kulshrestha
Thomas R Hoye
University of Minnesota · US

Funding

Synthesis Strategies for Bioactive Natural ProductsR01GM065597 · NIGMS · UNIVERSITY OF MINNESOTA TWIN CITIES · PI HOYE, THOMAS R. · 2002 to 2016
$3.1M
NIGMS NIH HHS GM-65597NIGMS NIH HHS R01 GM065597
6 · The paper itself

Abstract

We report an NMR chemical shift study of conformationally challenging seven-membered lactones (1-11); computed and experimental data sets are compared. The computations involved full conformational analysis of each lactone, Boltzmann-weighted averaging of the chemical shifts across all conformers, and linear correction of the computed chemical shifts. DFT geometry optimizations [M06-2X/6-31+G(d,p)] and GIAO NMR chemical shift calculations [B3LYP/6-311+G(2d,p)] provided the computed chemical shifts. The corrected mean absolute error (CMAE), the average of the differences between the computed and experimental chemical shifts for each of the 11 lactones, is encouragingly small (0.02-0.08 ppm for (1)H or 0.8-2.2 ppm for (13)C). Three pairs of cis versus trans diastereomeric lactones were used to assess the ability of the method to distinguish between stereoisomers. The experimental shifts were compared with the computed shifts for each of the two possible isomers. We introduce the use of a "match ratio"--the ratio of the larger CMAE (worse fit) to the smaller CMAE (better fit). A greater match ratio value indicates better distinguishing ability. The match ratios are larger for proton data [2.4-4.0 (av = 3.2)] than for carbon [1.1-2.3 (av = 1.6)], indicating that the former provide a better basis for discriminating these diastereomers.

Indexed as

Quantum TheoryCarbonLactonesMagnetic Resonance SpectroscopyMolecular ConformationProtonsReference StandardsCarbonLactonesProtons

Identifiers

PMID24354614
PMCPMC3955734
OpenAlexW2005674840

What OpenQuestion holds

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Registered trials

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Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.