Synthesis and 13 C‐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 1 H‐NMR and 13 C‐NMR spectroscopic investigations. The corresponding model compounds were synthetized and, according to 13 C‐NMR spectroscopic investigations, a part of the so far published NMR assignations have to be corrected.