The conformation of a tetratritylated α-cyclodextrin with unusual proton NMR

Tetratritylation of α-cyclodextrin (CD) and subsequent peracetylation of the partially tritylated mixture allowed the preparation and isolation of the symmetrical 6A,6B,6D,6E-tetratritylated α-CD in pure form. The 1H NMR spectra of the compound showed abnormal behaviour with the anomeric proton of one of the glycopyranosyl systems resonating below 3.0 ppm, which is exceptionally unusual. To understand this anomaly in the 1H NMR data, we performed a complete NMR analysis and using molecular modelling as a tool, we were able to obtain a conformation that can explain the observed NMR phenomenon.

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