BENZIL BENZILIC ACID REARRANGEMENT IN CROSS-LINKED MACROMOLECULAR SYSTEMS - EFFECT OF CROSS-LINKING

The effect of the molecular character and extent of crosslinking units on polymer-analogous benzil-benzilic acid rearrangement was investiga ted. A typical hydrophobic styrene-divinylbenzene copolymer and a hydr ophilic styrene-tetraethyleneglycol diacrylate copolymer were used as the polymer supports. Supports with crosslink densities varying from 2 to 20% were functionalized. The polymer-bound aldehydes were subjecte d to crossed benzoin condensation in the presence of benzaldehyde. The benzoin analogues were converted to benzils and then subjected to ben zil-benzilic acid rearrangement. The products were characterized by i. r. and C-13 n.m.r. spectroscopy and the extent of rearrangement was de termined by chemical methods.