Reacting cross-linked chloromethylated polystyrenes on 2

3-dimercaptopropanol (BAL) and sodium hydroxide under phase-transfer condition

a new type of insoluble polymer support containing a sulfhydryl and a hydroxyl group was synthesized (Ⅲ) (sulfhydryl capecity = 2.5 mmol/g). This BAL-resin being made to monoprotect symmetrical dialdehydes (terephthalal-dehyde)

an aldenhyde-resin was obtained (Ⅳ) (aldehyde group capacity =1.2 mmol/g). under the catalysis of phase-transfer

in benzene-wate system at room temperature and sodium hy-droxide as base

the free aldehyde group reacted on Witting reagents to give a p-formylstilbenes (VII) (yield=85.4%).