Two chalcone-derivative isomers, 4,4-diaminochalcone ( 4DAC ) and 3,3diaminochalcone ( 3DAC ), were synthesized and used as monomers together with tetracarboxylic dianhydrides to prepare novel photosensitive polyimides that contain a chalcone moiety in the main chain. The polyimides were characteriz
A facile synthesis of a novel polyacetal containing trehalose residue in the main chain
β Scribed by Naozumi Teramoto; Youhei Arai; Yoshinari Shibasaki; Mitsuhiro Shibata
- Publisher
- Elsevier Science
- Year
- 2004
- Tongue
- English
- Weight
- 141 KB
- Volume
- 56
- Category
- Article
- ISSN
- 0144-8617
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β¦ Synopsis
A novel polyacetal containing a,a-D-trehalose residue in the main chain was successfully synthesized by the reaction of a,a-D-trehalose with terephthalaldehyde bis(dimethyl acetal) in the presence of p-toluenesulfonic acid. As a result of examination of reaction condition, weight-average molecular weight Γ°M w Γ of the polyacetal ranged from 2000 to 8500 when measured by GPC. The polyacetal was soluble in dipolar aprotic solvents such as DMSO and DMF. The 1 H-NMR and MALDI-TOF MS spectra revealed that the polyacetal is composed of the molecules terminated by glucopyranosyloxy group, dimethylacetal group, and aldehyde group generated by the hydrolysis of dimethyl acetal group. The polyacetal with M w 8500 showed no glass transition temperature up to the decomposition temperature (325 8C).
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A novel class of prostaglandins containing a boronate in the a chain have been synthesized. The key steps in the synthesis were the preparation of the ylide containing the boronate and the subsequent Wittig reaction using the ylide.
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