Synthesis and photochemical reaction of cyclic oligomers:: Synthesis and photopolymerization of novel C-methylcalix[4]resorcinarene and p-alkylcalix[n]arene derivatives containing spiro ortho ether groups

New photoreactive calixarene derivatives containing Spiro ortho ester groups (calixarenes 3a-3c) were synthesized by the reaction of 2-bromomethyl-1,4,6-trioxaspiro[4.4]nonane with 2,8,14,20-tetramethyl-4,6,10,12,16,18,22,24-octakis(carboxymethoxy)calix[4]resorcinarene, 5,11,17,23,29,35-hexamethyl-37,38,39,40,41,42-hexakis(carboxymethoxy)calix[6]arene, and 5,11,17,23,29,35,41,47-octa-tert-butyl-49,50,51,52, 53,54,55,56-octakis-(carboxymethoxy)calix[8]arene, which were prepared by the reaction of C-methylcalix[4]resorcinarene,p-methylcalix[6]arene, and p-tert-butylcalix[S] arene, respectively. The thermal stability of the obtained calixarene derivatives containing Spiro ortho ester groups was examined with thermogravimetric analysis, and it was found that these calixarene derivatives had good thermal stability. The photoinitiated cationic polymerization of Spiro ortho ester groups in calixarene derivatives 3a-3c was examined with certain photoacid generators in the film state. Interestingly enough, the reaction of calixarene derivatives did not proceed with only photoirradiation; however, the reaction proceeded smoothly when the photoirradiation was followed by heating. Furthermore, calixarene 3a, composed of a C-methylcalix[4]resorcinarene structure, showed the highest photochemical reactivity in this reaction system. (C) 2002 Wiley Periodicals, Inc.