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Ring‐opening polymerization and copolymerization of a new benzylated 1,6‐anhydro‐3‐azido‐3‐deoxy‐β‐ D ‐allopyranose and synthesis of amino‐polysaccharides with 1,6‐α‐allopyranosidic structure

1997; Wiley; Volume: 198; Issue: 1 Linguagem: Inglês

10.1002/macp.1997.021980103

1521-3935

Kazuyuki Hattori, Takashi Yoshida, Toshiyuki Uryu,

Click Chemistry and Applications

Abstract Ring‐opening polymerization of a new anhydro‐hexose monomer having an azido group, 1,6‐anhydro‐3‐azido‐2,4‐di‐ O ‐benzyl‐3‐deoxy‐β‐ D ‐allopyranose (A3ABA), was carried out with Lewis acid catalysts to give a stereoregular (1→6)‐α‐ D ‐allopyranan derivative having the azido group at the C3 position. The number‐average molecular weights and specific rotations were 5.0 × 10 3 to 24.0 × 10 3 and +71° to +79°, respectively. Reduction of the azido groups into amino groups by lithium aluminium hydride and subsequent debenzylation of the benzyl group into hydroxyl groups by sodium in liquid ammonia gave 3‐amino‐3‐deoxy‐(1→6)‐α‐ D ‐allopyranan in good yield. In addition, copolymerization of A3ABA with 1,6‐anhydro‐2,3,4‐tri‐ O ‐benzyl‐β‐ D ‐glucopyranose (LGTBE) in the various feeds was carried out to afford the corresponding copolymers. The monomer reactivity ratios were calculated with the Kelen‐Tüdős method to be r A3ABA = 0.66 and r LGTBE = 1.67. After reduction of azido groups and deprotection of benzyl groups of the copolymers, new hetero‐polysaccharides having different contents of glucopyranose and 3‐amino‐allopyranose units were obtained.