Computer-Assisted 3D Structure Elucidation (CASE-3D): The Structural Value of 2 JCH in Addition to 3 JCH Coupling Constants.
Angew Chem Int Ed Engl
; 59(10): 3938-3941, 2020 03 02.
Article
in En
| MEDLINE
| ID: mdl-31917516
ABSTRACT
We present a method to use long-range CH coupling constants to derive the correct diastereoisomer from the molecular constitution of small molecules. A set of 79 2 JCH and 3 JCH values collected from a single HSQMBC experiment on a sample of strychnine were used in the CASE-3D (computer-assisted 3D structure elucidation) protocol. In addition to the most commonly used 3 JCH coupling constants, the subset of 32 2 JCH values alone showed an excellent degree of configuration selection. The study is mainly based on comparison of DFT-calculated 2,3 JCH values with experimental ones, critical for the case of 2 JCH . But the configuration selection also works well using 3 JCH values predicted from a semi-empirical Karplus-based equation limited to H-C-C-C fragments. The robustness, shown using strychnine as a proof of concept, makes the J-based CASE-3D analysis a viable option for the application in fields such as peptide and carbohydrate research, organic synthesis, natural-product identification and analysis, as well as medicinal chemistry.
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Language:
En
Journal:
Angew Chem Int Ed Engl
Year:
2020
Document type:
Article
Affiliation country:
United States