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Determination of the stereochemistry of γ‐Butyrolactones by DPFGSE‐NOE experiments
Author(s) -
Xie X.,
Tschan S.,
Glorius F.
Publication year - 2007
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.1965
Subject(s) - chemistry , stereocenter , diastereomer , vicinal , stereochemistry , cyclohexane , methylene , two dimensional nuclear magnetic resonance spectroscopy , nmr spectra database , molecule , furan , ring (chemistry) , nuclear magnetic resonance spectroscopy , spectral line , enantioselective synthesis , medicinal chemistry , organic chemistry , physics , astronomy , catalysis
The stereochemistry of γ‐butyrolactons tetrahydro‐6 a ‐phenylfuro[3,4‐ b ]furan‐2(3 H )‐one (1), 1,4,5,9 b ‐tetrahydro‐3 a ‐methylnaphtho[2,1‐ b ]furan‐2(3 aH )‐one (2), 1,4,5,9 b ‐tetrahydro‐3 a ‐methylfuro[2,3‐ c ]quinolin‐2(3 aH )‐one (3) and hexahydro‐furo[3,2‐ c ]benzofuran‐2‐one (4) was studied using DPFGSE‐NOE experiments. Compounds 1–3 contain two stereocenters, while 4 contains three. Both 1 H and 13 C spectra showed a single diastereomer of all the compounds. Routine 2D experiments (DQF)‐COSY, HMQC/HSQC, and HMBC were used to assign 1 H and 13 C spectra completely. Diastereotopic methylene protons with resolved 1 H NMR signals as well as protons of cyclohexane served as references for the construction of the spatial arrangement in the molecules. NOE contacts between protons attached to the stereocenter and the diastereotopic protons were thus used to determine the configuration of the molecules. Vicinal coupling constants 3 J assisted the assignment of the conformational arrangement of the cyclohexane ring of 4. Copyright © 2007 John Wiley & Sons, Ltd.