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Cationic ring‐opening polymerization of new 1,6‐anhydro‐β‐lactose derivatives
Author(s) -
Yoshida Takashi,
Yasuda Yuichi,
Hattori Kazuyuki,
Uryu Toshiyuki
Publication year - 1995
Publication title -
macromolecular rapid communications
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.348
H-Index - 154
eISSN - 1521-3927
pISSN - 1022-1336
DOI - 10.1002/marc.1995.030161202
Subject(s) - cationic polymerization , monomer , ring opening polymerization , polymer chemistry , chemistry , copolymer , polymerization , disaccharide , polymer , organic chemistry
Abstract Synthesis and cationic ring‐opening polymerization of new 1,6‐anhydro‐β‐lactose derivatives such as hexa‐ O ‐methylated (LSHME), tert ‐butyldimethylsilylated (LSHSE), and benzylated 1,6‐anhydro‐β‐lactoses (LSHBE) were first investigated. The disaccharide monomers were prepared by methylation, tert ‐butyldimethylsilylation, and benzylation of 1,6‐anhydro‐β‐lactose, respectively. It was found that LSHME was readily polymerized with such Lewis acid catalysts as PF 5 and SbCl 5 to give stereoregular 2,3‐di‐ O ‐methyl‐4‐ O ‐(2′,3′,4′,6′‐tetra‐ O ‐methyl‐β‐ D ‐galactopyranosyl)‐(1→6)‐β‐ D ‐glucopyranans which are comb‐shaped polysaccharide derivatives. However, LSHSE and LSHBE had almost no polymerizability. It was revealed that the ring‐opening polymerizability of the anhydrodisaccharide monomers was influenced by the steric hindrance of the hydroxyl‐protective groups. Ring‐opening copolymerization of LSHME with 1,6‐anhydro‐2,3,4‐tri‐ O ‐benzyl‐β‐ D ‐glucopyranose (LGTBE) in various ratios of monomer feeds was also examined to afford the corresponding copolymers. Structural analyses of the monomers and polymers were carried out by means of high resolution nuclear magnetic resonance spectroscopy.