Methylation of p-tert-Butylcalix[8]arene. Products Obtained in the Presence of Strong Bases.
Methylation of p-tert-butylcalix[8]arene with MeI in the presence of strong bases (NaH, BaO/Ba(OH)(2), or Cs(2)CO(3)) in THF has been investigated. Composition of the reaction mixtures differs remarkably from those obtained using weak bases and described in a preceding paper. Several previously unreported methylated products [two dimethoxy- (2(1,5) and 2(1,4)), a trimethoxy- (3(1,2,5)), a tetramethoxy- (4(1,2,3,6)), two pentamethoxy- (5(1,2,3) and 5(1,2,4)), and three hexamethoxy- (6(1,2), 6(1,3), and 6(1,4))] have been isolated. In many cases the substitution pattern was assigned unambiguously on the basis of spectroscopic evidence only, while in others chemical correlation with known compounds was required.
Cunsolo
Francesca
F
Istituto per lo Studio delle Sostanze Naturali di Interesse Alimentare e Chimico-Farmaceutico, C.N.R., Via del Santuario 110, I-95028 Valverde (CT), Italy.
Consoli
Grazia M. L.
GM
Piattelli
Mario
M
Neri
Placido
P