Chemoenzymatic synthesis of sucrose-containing aromatic polymers

A chemoenzymatic approach was developed to prepare sucrose-containing aroma tic polymers. The protease from Bacillus licheniformis catalyzed the transe sterification of sucrose with a diester of terephthalic acid in pyridine to give the mono- and diester products. At 45 degreesC, >70% of sucrose was c onsumed after 1 day and sucrose diester began to form after 6 days when >95 % of sucrose had been converted to sucrose monoester. The final yield of su crose diester after 20 days was 13.8%. The sucrose monoester was identified as sucrose 1'-terephthalate and the diester products consisted of sucrose 6,1'-diterephthalate and sucrose 6',1'-diterephthalate in a ratio of 2:1. T he sucrose diester products were polymerized with ethylene-glycol and ethyl ene-diamine to give poly(ethylene-terephthalate) and poly(ethylene-terephth alamide), with sucrose contained in the polymer backbone. The polycondensat ion reactions were carried out in dimethylsulfoxide (DMSO) at 70 degreesC u sing zinc acetate as a catalyst. The sucrose-containing polyester and polya mide were obtained at 65% yield for 24 h and at 73% yield for 12 h, respect ively. End-group analysis of the polymers by C-13-NMR or H-1-NMR in DMSO pr ovided a number average molecular weight of 3200 and 4300 Da, respectively. Structural analyses of the polymers were performed with H-1-NMR, 13C-NMR, and FTIR. On the basis of 13C-NMR, acylation of the C1', C6, and C6' hydrox yls were maintained in the polymer backbones. (C) 2001 John Wiley & Sons, I nc.