Abstract |
Direct O-alkylation of p-tert-butyldihomooxacalix[4]arene (1) with 2-(chloromethyl)pyridine hydrochloride and NaH in DMF provided six of the nine possible (2-pyridylmethoxy)dihomooxacalix[4]arene conformers in the cone conformation. Mono- and tetrasubstituted derivatives were obtained, as well as all four (1,2-, 1,3-, 1,4- and 2,3-) types of disubstituted compounds. The conformations and the substitution patterns were established by NMR spectroscopy (H-1, C-13, COSY, NOESY and TOCSY 1D). Front the same reaction, another tetrasubstituted derivative (6) in a 1,2-alternate A conformation was also isolated and characterised. (C) Wiley-VCH Verlag GmbH, 69451 Weinheim, Germany, 2002. |