首页 | 本学科首页   官方微博 | 高级检索  
     检索      


Condensation and Polycondensation of Terephthaldehyde with Methyl D‐Hexopyranosides
Authors:Jolanta Ma li&#x;ska‐Solich
Abstract:The condensation and polycondensations of terephthaldehyde ( 1 ) and methyl D ‐hexopyranosides (gluco‐, galacto‐ and mannopyranoside) are described. Methyl α‐D ‐glucopyranoside and methyl α‐D ‐galactopyranoside react with 1 to give mono‐ 5 a and 6 a and diacetals 5 b and 6 b . Their structures were confirmed by NMR and IR spectroscopy. The polycondensation of methyl α‐D ‐mannopyranoside ( 4 ) with 1 was studied in various solvents within the temperature range of 80–140°C. Regardless of the conversion or the initial comonomer feed ratios the composition of polycondensates depended on the reaction conditions leading to the formation of materials with diverse solubilities, molecular weights and optical properties. The regioselective polycondensation of 1 and 4 was examined by the 1H NMR spectroscopy of polymer 7 . In the case of five‐membered cyclic acetal units, mixtures of the endo‐H and exo‐H dioxolan‐2‐yl system diastereomers are formed. Experimental examples of functionalization via ester units in polymer molecules 8 are described and the efficiency of the reaction routes and procedures are evaluated. The molecular weight was estimated by size‐exclusion chromatography (SEC) measurements before and after the functionalization.
Keywords:
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号