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[摘要]：Considerable work has been invested in the area of computer-assisted structure elucidation (CASE) methods. As NMR techniques have been developed that provide more effective atom-to-atom connectivity information, it has become theoretically possible to do de novo structure elucidation based on 2D NMR datasets recorded for an unknown molecule. However, as annular (ring) nitrogen atoms become more prevalent in complex chemical structures, the ability to rely solely on 1H and 13C homo- and hetero-nuclear direct and long-range connectivity information to solve a structure correspondingly diminishes. Hence, we now wish to report the results of an investigation into the application of CASE methods with and without long-range 1H-15N data using posaconazole as a model compound, which has eight annular nitrogens in its structure. With the inclusion of 1H-15N data long-range data, the structure could be successfully determined in a few hours. Excluding the 1H-15N data caused the program to generate millions of candidate structures, none of which fit the data well enough to be stored. |
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