Beilstein J. Org. Chem.2021,17, 2939–2949, doi:10.3762/bjoc.17.203
components by COSY and HMBC correlations established 6-prenylated N-acetyltryptophan (Figure 5). The N-acetylation was evident from HMBC correlations from the amide (NH-11) and acetyl methyl protons (H-13) to the amide carbon (C-12), while prenylation at C-6 was supported by HMBC correlations from H-5 and H
Beilstein J. Org. Chem.2017,13, 1572–1582, doi:10.3762/bjoc.13.157
10.3762/bjoc.13.157 Abstract The enantioselectivity of β-cyclodextrin (β-CD) towards L- and D-N-acetyltryptophan (NAcTrp) has been studied in aqueous solution and the crystalline state. NMR studies in solution show that β-CD forms complexes of very similar but not identical geometry with both L- and D
crystallization, as a consequence of accumulation of many soft host–guest interactions and of the imposed crystallographic order, thus resulting in very dissimilar propensity of each enantiomer to produce crystals with β-CD.
Keywords: β-cyclodextrin; enantiomeric discrimination; N-acetyltryptophan; NMR; X-ray
. Moreover, trends in enantioselectivity do not follow trends in association constants, i.e., the association constants for the β-CD complexes of both enantiomers of N-acetyltyrosine, N-acetylphenylalanine and N-acetyltryptophan are in decreasing order, whereas their enantioselectivity (ratio of the binding
PDF
Graphical Abstract
Scheme 1:
Numbering scheme of one glucopyranose residue (G) of β-CD and the NAcTrp molecule; specific atom la...