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Long-range shielding effects in the (1)H NMR spectra of Mosher-like ester derivatives.

ABSTRACT: The relative magnitudes of the chemical shift differences (Deltadeltas) in the two diastereomers of menthyl esters of known chiral derivatizing agents (CDAs) were compared to those of the alpha-methoxy-alpha-trifluoromethyl-1-naphthylacetyl (MTN((1))A) analogues I. Discrimination of the terminal diastereotopic methyl resonances in esters of the homologous, symmetrical carbinols II was evaluated. Remarkably, the methyls differed in the MTN((1))A esters III even when n = 15; an unexpected crossover in the sign of the Deltadelta values was also observed.

SUBMITTER: Hoye TR

PROVIDER: S-EPMC2886499 | biostudies-literature | 2010 Apr

REPOSITORIES: biostudies-literature

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Long-range shielding effects in the (1)H NMR spectra of Mosher-like ester derivatives.

Hoye Thomas R TR Erickson Sara E SE Erickson-Birkedahl Sherrie L SL Hale Christopher R H CR Izgu Enver Cagri EC Mayer Michael J MJ Notz Patrick K PK Renner Matthew K MK

Organic letters 20100401 8

The relative magnitudes of the chemical shift differences (Deltadeltas) in the two diastereomers of menthyl esters of known chiral derivatizing agents (CDAs) were compared to those of the alpha-methoxy-alpha-trifluoromethyl-1-naphthylacetyl (MTN((1))A) analogues I. Discrimination of the terminal diastereotopic methyl resonances in esters of the homologous, symmetrical carbinols II was evaluated. Remarkably, the methyls differed in the MTN((1))A esters III even when n = 15; an unexpected crossove ...[more]

PMID: 20337423

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