Acid-catalyzed rearrangement of aromatic ethers. Model studies and application to imaging

A variety of polymers incorporating appropriate benzylic or allylic ether functionalities in their main-chain were shown to be excellent dry-developing imaging systems. In view of the excellent results which are obtained in the photocrosslinking of the copolymers, some of the mechanistic details of the crosslinking process were explored. In particular, much information can be obtained from model studies with low molecular weight compounds instead of the copolymer. The models chosen for this study were benzyl acetate, or 4-isopropyl-benzyl acetate, and 4-isopropyl phenol. The model reactions were carried out within the confines of a NMR tube in deuterochloroform using 10 mole % triflic acid to trigger the reaction instead of the photogenerated superacid.