Synthesis and 13C‐NMR Spectroscopy of Methylated beta‐Cyclodextrins

The methylated analogues of ß‐cyclodextrin dissolve in cold water 10 – 20 times better than ß‐cyclodextrin itself, however, quite unusually on heating they crystallize from the solution. The structure of heptakis‐(2,6‐di‐O‐methyl)‐ and heptakis‐(2,3,6‐tri‐O‐methyl)‐ß‐cyclodextrin was proved by gas‐liquid chromatographic and 1H‐NMR and 13C‐NMR spectroscopic investigations. The corresponding model compounds were synthetized and, according to 13C‐NMR spectroscopic investigations, a part of the so far published NMR assignations have to be corrected.