An attempt to synthesize the two monomers of CDTOH: Unexpected NMR and X-ray diffraction crystal analysis

Two monomer compounds of CDTOH, 6A-deoxy-6A-(4-(2-hydroxyethyl)-1H-1,2,3-triazol-1-yl)-per-O-methylated ?-cyclodextrin 4 and 6A-deoxy-6A-(4-(2-hydroxyethyl)-1H-1,2,3-triazol-1-yl) 7, have been synthesized via click chemistry. The structures were confirmed by 1H NMR, 13C NMR ESI-HRMS. In comparison to the spectra compound intermediate 6, two sets peaks in high field 7 are somewhat unusual. X-ray single-crystal analysis showed existence an intramolecular hydrogen bond between CH2OH donor glucose B terminal hydroxy acceptor side chain, leading 4-(2-hydroxyethyl)-1H-1,2,3-triazole group protruding outside cavity embedding hydrophobic adjacent molecule (interinclusion) form interlocked helical columnar superstructure.