A novel method for the preparation of inherently chiral calixarenes is described by direct introduction of a substituent in para-acetamido substituted calixarenes. Bromination and nitration of mono(acetamido)calixarenes 5, 6 afforded calixarenes 7¿10, in which the substituent was selectively introduced adjacent to the acetamido moiety, in 58¿98% yield. Bromination of bis(acetamido)calixarene 13 gave a mixture from which dibromo- (14) and tribromocalixarene 15 were isolated in 10% and 22% yield, respectively. The structure of 14 was confirmed by single-crystal X-ray structure determination. Nitration of 13 gave 4,16-dinitro- (16) and 4,18-dinitrocalixarene 17 in 53% and 18% yield, respectively.
Verboom, W., Bodewes, P., Bodewes, P. J., van Essen, G., Timmerman, P., van Hummel, G. J., ... Reinhoudt, D. (1995). A novel approach to inherently chiral calixarenes by direct introduction of a substituent at the meta position. Tetrahedron, 51(2), 499-512. https://doi.org/10.1016/0040-4020(94)00911-D