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Total structural assignment and absolute configuration of terreinol by 13 C and 1 H NMR
Author(s) -
de Macedo Fernando César,
Marsaioli Anita Jocelyne
Publication year - 2005
Publication title -
magnetic resonance in chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.483
H-Index - 72
eISSN - 1097-458X
pISSN - 0749-1581
DOI - 10.1002/mrc.1531
Subject(s) - chemistry , absolute configuration , sign (mathematics) , stereochemistry , metabolite , carbon 13 nmr , carbon fibers , aspergillus terreus , computational chemistry , mathematical analysis , biochemistry , materials science , mathematics , food science , composite number , composite material
The carbon–carbon connectivity of terreinol, a new metabolite isolated from Aspergillus terreus , and its previous 13 C assignments were confirmed by a two‐dimensional INADEQUATE experiment using a few milligrams of the compound with natural 13 C abundance. The carbon–carbon correlations were determined by computational analysis (with >99% probability) of this experiment. Additionally, the absolute configuration of terreinol was achieved indirectly via its corresponding secondary alcohol by the modified Mosher method allied to conformational analysis. The shielding effect of the phenyl group of methoxytrifluoromethylphenylacetic acid (MTPA) on the substituents of the carbonylic centre gave a fully regular Δδ SR sign distribution, allowing reliable assignment of the R configuration for terreinol. Copyright © 2004 John Wiley & Sons, Ltd.