Structure Assignment by

This is the structure assigned by Chem. Abs. to the claimed benzotriazolium nitroimidate below. The editor suspects they are right and that the nitroamine... 

Programs and data are stored on disks or diskettes. Using a bank of chemical shift data and coupling constants of several thousand compounds, stored on magnetic tapes or disks, and the appropriate software, partial structural assignments by the computer are possible [48],... 

This is the structure assigned by chem. Abs. to the claimed benzotriazolium 1-nitro-imidate above. The editor suspects they are right and that the nitroamine structure should also be considered for the 2- isomer. The uc/ -nitro structures are also possible. See Benzotriazolium 1-nitroimidate See also N—NITRO COMPOUNDS... 

It should be noted that the structures assigned by von Auwers to these acylpyrazoles are not strictly proved. His attempts to confirm structure by a comparison of molecular refractions156 are scarcely conclusive, as often the exaltations of a pair of isomers are practically the same.153 The isomerism of acyl derivatives was considered in detail by von Auwers,83,86,156,281 but the data often seem quite contradictory. 

Whereas the structural assignment by one-dimensional 13C NMR spectroscopy is unambiguous in the case of D2-Cj(,2,51 Achiba and co-workers were able to determine the carbon atom connectivity by 2D 13C NMR INADEQUATE (incredible natural abundance double-quantum transfer experiment) analysis performed on an isotopically enriched sample (20% 13C).58 In particular, they found that the observed chemical shifts correlate well with the curvature of the spheroid, the more strongly pyramidalized carbon atoms being shifted toward lower magnetic field. 

Another series of interesting thiosugars was prepared by Schubert by the action of cysteine on the aldoses. By analogy with the structure assigned by this same author to the reaction product of cysteine with ordinary aldehydes, these new compounds may be formulated as the open chain forms ... 

The isolation from Buxus sempervirens, and their structural assignment by physical and chemical methods, of N-benzoylbuxodienine E (44a), /V-benzoyl-0-acetylbuxodienine E (44b), and N-benzoylcyclovirobuxenine E (45) have been reported. 

Compounds (107 R, R = Me) and (108) transport chloride and bromide ions from one aqueous solution to another. The cyclotrisilane (109), prepared from commercially available 3-chloro-propyltrimethoxysilane in nine steps <88TL297>, was structurally assigned by mass spectrometry and H and C NMR spectroscopy. A solution of (109) in dichloromethane transported chloride or bromide ions from one aqueous solution to another, but not fluoride or iodide ions host-guest complexes of type (110) (Equation (10)) were postulated as intermediates in the transport processes. 

Simonis continued to prove the correct structural assignment by degradation and began exploring the scope and limitation of the reaction As more co-workers joined in the exploration, many were convinced that Simonis did not make the chromone, but actually made the coumarin and that the structure was merely misassigned. While descriptions of early work solely on the Simonis chromone synthesis are lacking, reviews on the synthesis of coumarins (the Pechmann reaction) typically include an overview on the Simonis chromone synthesis " ... 

Carter CAG, Tinto WF, Reynolds WF, McLean S (1993) Quassinoids from Quassia multiflora Structural Assignments by 2D NMR Spectroscopy. J Nat Prod 56 130-133... 

Smith C R, Madrigal R V, Weisleder D, Mikolajczak K L, Highet R J 1976 Potamogetonin, a new furanoid diterpene. Structural assignment by carbon-13 and proton magnetic resonance. J Org Chem 41 593-596... 

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