EFFECT OF POLYMER ARCHITECTURE ON THE EFFICIENCY OF ACYL TRANSFER-REACTIONS

A series of spacer-modified polystyrene-supported hydroxamic esters an d hydroxamic dithiocarbonic anhydrides were prepared starting from div inyl benzene and ethyleneglycol dimethacrylate crosslinked polystyrene resins through multistage polymer-analogous reactions. Acyl transfer reactions using these polymer-supported hydroxamic acylating agents co ntaining spacer arms of various lengths were carried out. The investig ation revealed a sharp increase in reactivity as the length of the spa cer arm was increased from zero methylene spacer to five methylene spa cers. Investigations were also carried out to correlate the extent of acyl transfer with the nature and degree of crosslinking and the relat ive polarity of the polymer network. It was found that the extent of f unctionalization in each of the polymer analogous reactions and the ex tent of acylation reaction decreased with an increase in the degree of crosslinking. (C) 1996 John Wiley & Sons, Inc.