¹³C-NMR of Piperidine-Cyclodextrin Inclusion Compoundst

Abstract

¹³C-NMR data have been obtained for piperidine, three kinds of hydroxypiperidines, six kinds of methylpiperidines and one methyl-substituted piperidinone in the presence or absence of α or β-cyclode xtrin. Larger inclusion shifts for these piperidines are observed in deuterium wade than in 50% dimethyl-d6 sulfoxide aqueous solution. It is suggested, based on the 'inclusion shifts, that the opposite end to nitrogen atom is preferentially included into cyclo, dextrin. Hydroxyl group is disadvantageous for inclusion and the substituent on the piperidine ring mars sclear orientation of inclusion. Methyl group is favorably included into the cyclodextrin cavity, however random orientations are still taking place in the case of N-methylpiperid.