ISSN:
1573-1111
Keywords:
Chemically-modified cyclodextrins
;
conformational analysis
;
NMR spectroscopy
Source:
Springer Online Journal Archives 1860-2000
Topics:
Chemistry and Pharmacology
Notes:
Abstract The observation that per-2,6-O-methyl-3-O-benzoyl-α-cyclodextrin (1) displays some unusual conformational behaviour in solution has led to a detailed investigation by (dynamic) NMR spectroscopy of the equilibration process that occurs in solutions of per-2,3-O-benzoyl-α-cyclodextrin (3) and some related compounds (7–9) between conformational isomers with averagedC 6 andC 3 molecular symmetries in certain organic solvents such as benzene, dichloromethane, and chloroform. The solvent dependence of the conformational equilibrium is also reflected in a spread of values for the specific optical rotations for 3 from +9° in 1,1,2,2-tetrachloroethane, where there is a degenerate equilibrium between species withC 3 molecular symmetry, to +92° in acetone where a species with averagedC 6 symmetry is present.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF01053857
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