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Acetal Linkage (acetal + linkage)
Selected AbstractsSynthesis of a New Type of Glycosidic Linkage: Acetal-Linked Disaccharides and Trisaccharides of Acyclic and Cyclic Sugars,EUROPEAN JOURNAL OF ORGANIC CHEMISTRY, Issue 15 2005Soni Kamlesh Madhusudan Abstract New types of di- and trisaccharides related to a unique trisaccharide present in the cell walls of Proteus have been synthesized by coupling of acyclic sugar dithioacetals and di- and monohydroxy cyclic sugars. In this class of compounds an acyclic sugar is linked to a cyclic sugar through an acetal linkage. The formation of these acetal-linked pseudodi- and-trisaccharides has been achieved by a generalized reaction procedure mediated by 1,3-dibromo-5,5-dimethylhydantoin under mild, metal-free and neutral conditions. Sixteen protected and twelve deprotected di- and trisaccharides related to the trisaccharide found in the Proteus cell wall have been synthesized. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005) [source] Novel multisubstrate inhibitors of mammalian purine nucleoside phosphorylaseACTA CRYSTALLOGRAPHICA SECTION D, Issue 11 2005Angela V. Toms In an effort to develop potent multisubstrate-analog inhibitors of purine nucleoside phosphorylase (PNP), three nucleoside phosphonates were designed utilizing structural information from the previously reported structures of complexes of bovine PNP with substrates and products. The nucleoside phosphonates contain an acetal linkage at the O2, and O3, positions and a two-C-atom spacer between the ribose and phosphate moieties. The linkage enables the compounds to simultaneously occupy the purine-, ribose- and phosphate-binding sites. The chemical syntheses, inhibition profiles and structural characterization of these novel multisubstrate analog inhibitors with bovine PNP are described. [source] Poly(tetramethylene ether) glycol containing acetal linkages: New PTMG-based polyol for chemically recyclable polyurethane thermoplastic elastomerJOURNAL OF POLYMER SCIENCE (IN TWO SECTIONS), Issue 5 2008Tamotsu Hashimoto To develop new chemically recyclable polyurethane elastomers, the poly(tetramethylene ether) glycol (PTMG) containing acetal linkages (PTMG-Acetal-OH) was prepared and subjected to the polyurethane synthesis with 4,4(-diphenylmethane diisocyanate (MDI) and 1,4-butanediol (BD; chain-extender). The obtained polyurethane (PTMG-Acetal-PU) shows very similar mechanical and thermal properties to those of the conventional PTMG-based thermoplastic polyurethane elastomers (PTMG-PU). The acid treatment of PTMG-Acetal-PU at room temperature caused hydrolysis reaction of their acetal units to regenerate PTMG as a degradation product. [source] | ||||||||||