Recursos de colección

Hokkaido University Collection of Scholarly and Academic Papers (135.711 recursos)

HUSCAP (Hokkaido University Collection of Scholarly and Academic Papers) contains peer-reviewed journal articles, proceedings, educational resources and any kind of scholarly works of Hokkaido University.

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Mostrando recursos 1 - 2 de 2

  1. Advanced NMR approaches for a detailed structure analysis of natural products.

    Fukushi, Eri
    Some new nuclear magnetic resonance (NMR) approaches to elucidate chemical structures, which have not been determined by routine NMR methods, are presented. Selective detection of methine (CH), methylene (CH₂), or methyl (CH₃) signals in each subspectrum by editing NMR methods was utilized to reduce the complexity in crowded spectra. It also increased the peak separation and enhanced the sensitivity by limiting the measuring area of the 2D spectra. Several 2D methods to measure ²'³J CH values, which are useful for stereochemical assignment are then introduced. To determine the structure of a highly hydrogen-deficient molecule, efficient correlation methods for long-range ¹³C–¹³C...
    - 01-mar-2018

  2. Application of 1D BIRD or X-filtered DEPT long-range C-C relay for detection of proton and carbon via four bonds and measuring long-range C-13-C-13 coupling constants

    Fukushi, Eri; Kawabata, Jun
    We propose the C-13-detecting 1D DEPT long-range C-C relay to detect super long-range H-C connectivity via four bonds (H-1-C-13-X-X-C-13, X represents C-12 or heteronuclear). It is derived from the DEPT C-C relay which detects the H-C correlations via two bonds (H-1-C-13-C-13) by setting the delays for J(CC) in the C-C relay sequence to the (LR)J(CC). This sequence gives correlation signals split by small (LR)J(CC), which seriously suffers from residual center signal. The unwanted signal is due to long-range C-H couplings ((LR)J(CH)). The expected relayed magnetization transfer (1)J(CH) -> (LR)J(CC) occurs in the H-1-C-13-X-(X)-C-13 isotopomer, whereas the unwanted signal of (LR)J(CH)...
    - 01-mar-2018

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