Conformational Isomerism of Calix[6]arenes: Isolation of Two Conformational Isomers of the 1,2-Bis(p-tert-butylbenzyl) Ether of p-tert-Butylcalix[6]arene

Journal of Organic Chemistry

Volumn 58, Issue 24, 1993, Pages 6535-6537

  Neri, Placido ^a   Rocco, Concetta ^a   Consoli, Grazia M L ^a   Piattelli, Mario ^a  

^a CNR   (Italy)

Author keywords

[No Author keywords available]

Indexed keywords

EID: 0000333910     PISSN: 00223263     EISSN: 15206904     Source Type: Journal    
DOI: 10.1021/jo00076a002     Document Type: Article

References (18)

1. Gutsche, C. D. Calixarenes; Stoddart, J. F., Ed.; The Royal Society of Chemistry; Cambridge, 1989.
2. Calixarenes, a Versatile Class of Macrocyclic Compounds; Vicens, J.; Böhmer, V., Eds.; Kluwer. Dordrecht, 1991.
3. Iwamoto, K.; Araki, K.; Shinkai, S. Tetrahedron 1991, 47, 4325.
4. Gutsche, C. D.; Bauer, L. J. J. Am. Chem. Soc. 1985, 107, 6059.
5. Gutsche, C. D.; Rogers, J. S.; Stewart, D.; Su, K.-A. Pure Appl. Chem. 1990, 62, 485.
6. Rogers, J. S.; Gutsche, C. D. J. Org. Chem. 1992, 57, 3152.
7. Kanamathareddy, S.; Gutsche, C. D. J. Org. Chem. 1992, 57, 3160.
8. Casnati, A.; Minari, P.; Pochini, A.; Ungaro, R. J. Chem. Soc., Chem. Commun. 1991, 1413.
9. Neri, P.; Foti, M.; Ferguson, G.; Gallagher, J. F.; Kaitner, B.; Pons, M.; Molins, M. A.; Giunta, L.; Pappalardo, S. J. Am. Chem. Soc. 1992, 114, 7814.
10. Neri, P.; Pappalardo, S. J. Org. Chem. 1993, 58, 1048.
11. A similar debenzylation procedure has been used in the synthesis of caliz[4]arene derivatives as a deprotection method: Iwamoto, K.; Shinkai, S. J. Org. Chem. 1992, 57, 7066.
12. Various methoxy-p-tert-butylcaliz[6]arenes, but not 5, have been recently described: Janssen, R. G.; Verboom, W.; Reinhoudt, D. N.; Casnati, A.; Freriks, M.; Pochini, A.; Ugozzoli, F.; Ungaro, R.; Nieto, P. M.; Carramolino, M.; Cuevas, F.; Prados, P.; de Mendoza, J. Synthesis 1993, 380.
13. A similar behavior has been observed for a tetraethoxy-p-tert-butylcalix[4]arene: Araki, K.; Iwamoto, K.; Shinkai, S.; Matsuda, T. Chem. Lett. 1989, 1747.
14. Sandström, J. Dynamic NMR Spectroscopy; Academic Press; London, 1982; pp. 143–146.
15. See also: Günther, H. NMR Spectroscopy; John Wiley & Sons; Chichester, 1980; pp. 245–247.
16. For the determination of calix[4]arene conformation a single rule, based on the chemical shift of the pertinent ArCHjAr carbon (29–33 ppm, syn-orientation and 38–40 ppm anti-orientation of the adjacent aromatic rings), has been proposed: Jaime, C.; de Mendoza, J.; Prados, P.; Nieto, P. M.; Sanchez, C. J. Org. Chem. 1991, 56, 3372. This rule appears to be to some extent also valid for calix[6]arenes (see ref 6a).
17. The program used was MacroModel V2.5 by Still, W. C. et al. Department of Chemistry, Columbia University, New York, 1989.
18. For the importance of the stabilizing effect of these interactions in similar compounds see: Kobayaahi, K.; Asakawa, Y.; Kikuchi, Y.; Toi, H.; Aoyama, Y. J. Am. Chem. Soc. 1993, 115, 2648.