Campus Units

Chemistry

Document Type

Article

Publication Version

Published Version

Publication Date

2015

Journal or Book Title

The Journal of Organic Chemistry

Volume

80

Issue

20

First Page

9967

Last Page

9972

DOI

10.1021/acs.joc.5b01516

Abstract

2,2,6,6-Tetramethylpiperidinyl-masked 1,2-diols exhibited stereochemistry-dependent hydroxyl proton chemical shifts: ca. 7 ppm for the syn diastereomer and ca. 2 ppm for the anti diastereomer. A computational search for low energy geometries revealed that the syn isomer favors a six-membered ring hydrogen bond to nitrogen and the anti isomer favors a five-membered ring hydrogen bond to oxygen. The computed low energy conformations were found to have a large difference in hydroxyl proton shielding that was reflected in the experimental chemical shift difference. This chemical shift difference was observed in a broad range of solvents, and thus may be useful as a stereochemical probe. The stereochemistry-dependent conformation and chemical shift signature appeared to be due to a syn pentane interaction between the gem-dimethyl groups on the 2,2,6,6-tetramethylpiperidinyl moiety.

Comments

Reprinted (adapted) with permission from J. Org. Chem., 2015, 80 (20), pp 9967–9972. Copyright 2015 American Chemical Society.

Copyright Owner

American Chemical Society

Language

en

File Format

application/pdf

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