A compound ethyl(5S,6R)-2-(4-methylphenyl)-6-[(1R)-tert-butyldimethylsilyloxyethy]-penem-3-carboxylate was synthesized through displacement,acylation and Wittig cyclization reaction of optically active material(3R,4R)...A compound ethyl(5S,6R)-2-(4-methylphenyl)-6-[(1R)-tert-butyldimethylsilyloxyethy]-penem-3-carboxylate was synthesized through displacement,acylation and Wittig cyclization reaction of optically active material(3R,4R)-3-[(1R)-tert-butyldimethylsilyloxyethyl]-4-acetoxy-2-azetidi-none(4AA)upon thionocarboxlic acid.The intermediates and the target product were characterized by 1HNMR,IR,elementary analysis and MS.展开更多
A series of hyperbranched polyesters with controlled inherent viscosities have been prepared by polycondensation of 3,5 bis(trimethylsiloxy) benzoyl chloride with sililated p methyl aniline under various molar ratios....A series of hyperbranched polyesters with controlled inherent viscosities have been prepared by polycondensation of 3,5 bis(trimethylsiloxy) benzoyl chloride with sililated p methyl aniline under various molar ratios. After reacted with acid chlorides in o dichlorobenzene, the functionalization of these polyesters was readily accomplished. The end groups of the crude polymers were effectively transferred into vinylic and ethynylic groups in high yields(>85%) as calculated by 1H NMR spectra without any change in their inherent viscosities.展开更多
文摘A compound ethyl(5S,6R)-2-(4-methylphenyl)-6-[(1R)-tert-butyldimethylsilyloxyethy]-penem-3-carboxylate was synthesized through displacement,acylation and Wittig cyclization reaction of optically active material(3R,4R)-3-[(1R)-tert-butyldimethylsilyloxyethyl]-4-acetoxy-2-azetidi-none(4AA)upon thionocarboxlic acid.The intermediates and the target product were characterized by 1HNMR,IR,elementary analysis and MS.
文摘A series of hyperbranched polyesters with controlled inherent viscosities have been prepared by polycondensation of 3,5 bis(trimethylsiloxy) benzoyl chloride with sililated p methyl aniline under various molar ratios. After reacted with acid chlorides in o dichlorobenzene, the functionalization of these polyesters was readily accomplished. The end groups of the crude polymers were effectively transferred into vinylic and ethynylic groups in high yields(>85%) as calculated by 1H NMR spectra without any change in their inherent viscosities.
