PREPARATION OF POLYMERIC DIKETONES AND THEIR CONVERSION TO POLYMERIC HYDROXY-ACIDS IN CROSS-LINKED POLYMERIC MATRICES

Supports of polystyrene (PS) crosslinked with divinylbenzene (DVB) wit h varying crosslink densities were prepared and furnished with 1,2-dik eto functions through a series of polymer-analogous reactions. Crossed benzoin condensation between polymeric aldehyde (formylated polystyre ne) and substituted low-molecular aldehydes gives a set of mixed alpha -hydroxy ketones. These polymeric benzoin analogues were converted to alpha-diketones by oxidation. The polymeric systems containing alpha-d iketo functions were subjected to rearrangement under basic conditions into hydroxy acids. The products were characterized by IR and C-13 CP -MAS NMR spectroscopy and by chemical methods. The rearrangement was o bserved to be facile in these highly crosslinked networks in spite of the environmental constraints imposed by the rigid and high-molecular- weight polymeric backbone.