Matches in SemOpenAlex for { <https://semopenalex.org/work/W2022385882> ?p ?o ?g. }
- W2022385882 endingPage "150" @default.
- W2022385882 startingPage "134" @default.
- W2022385882 abstract "Complete analysis of the 1H and 13C NMR spectra obtained with and without a chemical shift reagent (Eu(fod)3), of bis-lactim ether 1 (Schöllkopf auxiliary) and monosubstituted 3- or 2-{(2R,5S or 2S,5S)-5-isopropyl-3,6-dimethoxy-2,5-dihydropyrazin-2-yl]methyl}-1H-indoles is presented using gradient-selected one-dimensional (1D) and two-dimensional NMR techniques, such as 1D TOCSY, 1D NOESY (DPFGSE NOE), gCOSY, NOESY, ROESY gHETCOR, gHSQC and gHMBC. The contour plot of the gCOSY spectrum of 1–10 revealed cross peaks arising from the five-bond coupling between the H2 and H5 resonances of the dihydropyrazine ring for syn- (5JH2, H5 = 4–5.7 Hz) and for anti-isomers (5JH2, H5 = 3.4–3.8 Hz). The magnitude of the coupling constant was utilized to distinguish between the syn- and the anti-isomers (diastereomers). The precise values of nJHH (n = 3, 4, 5, 6) coupling constants for the indole and 2,5-dihydropyrazine moieties deduced from the calculated NMR spectra were supported by 1D TOCSY and gCOSY experiments and gauge invariant atomic orbital (GIAO) calculations. The magnitude of the coupling constants (5JH2, H5) indicates that the dihydropyrazine ring exists in a boat conformation. In both isomers, the indole group adopts a ‘folded’ conformation in which one diastereotopic face is effectively shielded by the aromatic benzene ring of the indole. This is supported by gradient-selected 1D NOESY and 2D NOESY experiments. Theoretical calculations of the conformation were performed to support the through-space shielding effect of the aromatic indole moiety based on the DFT/GIAO calculated 1H NMR data (chemical shifts and coupling constants) for 2-syn- and 2-anti-diastereomers in CDCl3. Copyright © 2009 John Wiley & Sons, Ltd." @default.
- W2022385882 created "2016-06-24" @default.
- W2022385882 creator A5019813856 @default.
- W2022385882 creator A5025718822 @default.
- W2022385882 creator A5026063536 @default.
- W2022385882 creator A5042268526 @default.
- W2022385882 date "2009-12-08" @default.
- W2022385882 modified "2023-10-16" @default.
- W2022385882 title "Complete analysis of the <sup>1</sup> H and <sup>13</sup> C NMR spectra of diastereomeric mixtures of (R,S- and S,S-)-3,6-dimethoxy-2,5-dihydropyrazine-substituted indoles and their conformational preference in solution" @default.
- W2022385882 cites W153285181 @default.
- W2022385882 cites W1963493144 @default.
- W2022385882 cites W1965877314 @default.
- W2022385882 cites W1967531940 @default.
- W2022385882 cites W1967635415 @default.
- W2022385882 cites W1970911164 @default.
- W2022385882 cites W1971213751 @default.
- W2022385882 cites W1973639151 @default.
- W2022385882 cites W1979844089 @default.
- W2022385882 cites W1980327377 @default.
- W2022385882 cites W1981660112 @default.
- W2022385882 cites W1984993740 @default.
- W2022385882 cites W1988649845 @default.
- W2022385882 cites W1995042715 @default.
- W2022385882 cites W1995055087 @default.
- W2022385882 cites W1996513705 @default.
- W2022385882 cites W2001614462 @default.
- W2022385882 cites W2005302972 @default.
- W2022385882 cites W2014970353 @default.
- W2022385882 cites W2017264970 @default.
- W2022385882 cites W2017879717 @default.
- W2022385882 cites W2019435294 @default.
- W2022385882 cites W2022471410 @default.
- W2022385882 cites W2025624195 @default.
- W2022385882 cites W2027109722 @default.
- W2022385882 cites W2027593691 @default.
- W2022385882 cites W2036883327 @default.
- W2022385882 cites W2037897795 @default.
- W2022385882 cites W2037913155 @default.
- W2022385882 cites W2038083805 @default.
- W2022385882 cites W2039812585 @default.
- W2022385882 cites W2044961513 @default.
- W2022385882 cites W2046711501 @default.
- W2022385882 cites W2050940897 @default.
- W2022385882 cites W2054164390 @default.
- W2022385882 cites W2057341346 @default.
- W2022385882 cites W2057631031 @default.
- W2022385882 cites W2068608897 @default.
- W2022385882 cites W2068744668 @default.
- W2022385882 cites W2069324475 @default.
- W2022385882 cites W2069415196 @default.
- W2022385882 cites W2069424952 @default.
- W2022385882 cites W2080640510 @default.
- W2022385882 cites W2081639673 @default.
- W2022385882 cites W2082720200 @default.
- W2022385882 cites W2083622601 @default.
- W2022385882 cites W2084619794 @default.
- W2022385882 cites W2085577644 @default.
- W2022385882 cites W2085590299 @default.
- W2022385882 cites W2089727305 @default.
- W2022385882 cites W2089887286 @default.
- W2022385882 cites W2090234236 @default.
- W2022385882 cites W2094288780 @default.
- W2022385882 cites W2122101131 @default.
- W2022385882 cites W2133232507 @default.
- W2022385882 cites W2153376345 @default.
- W2022385882 cites W2155093520 @default.
- W2022385882 cites W2161233078 @default.
- W2022385882 cites W2162516131 @default.
- W2022385882 cites W2163768517 @default.
- W2022385882 cites W2172892105 @default.
- W2022385882 cites W2175759555 @default.
- W2022385882 cites W2179162529 @default.
- W2022385882 cites W2313876753 @default.
- W2022385882 cites W2315690155 @default.
- W2022385882 cites W2329728472 @default.
- W2022385882 cites W2331664289 @default.
- W2022385882 cites W2950090080 @default.
- W2022385882 cites W2950870842 @default.
- W2022385882 cites W2951962523 @default.
- W2022385882 cites W2952007307 @default.
- W2022385882 cites W2952134232 @default.
- W2022385882 cites W4235638143 @default.
- W2022385882 cites W572810095 @default.
- W2022385882 cites W2002056727 @default.
- W2022385882 cites W2034098193 @default.
- W2022385882 doi "https://doi.org/10.1002/mrc.2556" @default.
- W2022385882 hasPubMedId "https://pubmed.ncbi.nlm.nih.gov/19998390" @default.
- W2022385882 hasPublicationYear "2009" @default.
- W2022385882 type Work @default.
- W2022385882 sameAs 2022385882 @default.
- W2022385882 citedByCount "4" @default.
- W2022385882 countsByYear W20223858822014 @default.
- W2022385882 countsByYear W20223858822015 @default.
- W2022385882 countsByYear W20223858822019 @default.
- W2022385882 crossrefType "journal-article" @default.
- W2022385882 hasAuthorship W2022385882A5019813856 @default.
- W2022385882 hasAuthorship W2022385882A5025718822 @default.
- W2022385882 hasAuthorship W2022385882A5026063536 @default.