Regio- and stereoselective cyclopolymerization of 1,2 : 4,5-dianhydro-3-O-methyl-xylitol leading to a novel polycarbohydrate of (2→5)-1,4-anhydro-3-O-methyl-pentitol

Abstract

SUMMARY: (2e5)-1,4-Anhydro-3-O-methyl-pentitol, which is a novel carbohydrate polymer without an anomeric linkage, was synthesized by cationic cyclopolymerization of 1,2 : 4,5-dianhydro-3-O-methylxylitol. When BF 3 N OEt 2 was used as the initiator, soluble polymers were obtained in 28 to 50% yield. These polymers have number-average molecular weights of 1150 to 2 340 corresponding to an average degree of polymerization of 8.8 to 18.0. It was confirmed by 13 C NMR that the resulting polymer mainly consists of 1,4-anhydro-3-O-methyl-DL-arabinitol units.

Cyclopolymerizations: Synthetic Tools for the Precision Synthesis of Macromolecular Architectures

“…The cationic 18). 120 The anionic polymerization of the monomer by t-BuOK leads to an insoluble product.…”

“…The cationic polymerization of 1,2:4,5-dianhydro-3- O -methyl-xylitol ( 40 ) by BF 3 ·OEt 2 affords mainly a polymer containing 1,4-anhydro-3- O -methyl- d , l -arabinitol units, in addition to the minor unit with 1,4-anhydro-3- O -methyl- d , l -adonitol structure (A; Figure ). The anionic polymerization of the monomer by t -BuOK leads to an insoluble product.…”

Cyclopolymerization of 1,2:5,6-Diepithio-3,4- di-O-methyl-1,2,5,6-tetradeoxy-d-mannitol and -l-iditol Leading to a Novel Thiosugar Polymer

“…Previously, we reported that the cyclopolymerization of 1,2:5,6-dianhydrohexitol proceeded through the regio-and stereoselective mechanism to give a stereoregular polymer such as (1f6)-2,5anhydrohexitol. [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17] The structural characteristic of the polymers is the lack of an anomeric linkage, which is quite different from naturally occurring polysaccharides. In addition, (1f6)-2,5-anhydro-D-glucitol derivatives showed a selective binding ability for metal cations, and a chiral discrimination property, and the 3,4-di-Osulfonylated polymer induced lymphocyte activation.…”

“…On the other hand, the functional property of artificial polysaccharides is expected to differ from that of natural ones; therefore, there is great interest in a synthetic method leading to a novel type of polysaccharide. Previously, we reported that the cyclopolymerization of 1,2:5,6-dianhydrohexitol proceeded through the regio- and stereoselective mechanism to give a stereoregular polymer such as (1→6)-2,5-anhydrohexitol. − The structural characteristic of the polymers is the lack of an anomeric linkage, which is quite different from naturally occurring polysaccharides. In addition, (1→6)-2,5-anhydro- d -glucitol derivatives showed a selective binding ability for metal cations, and a chiral discrimination property, and the 3,4-di- O -sulfonylated polymer induced lymphocyte activation. − …”

Ring-Opening and Ring-Forming Polymerization of 1,2:5,6:9,10-Triepoxydecane Leading to a Highly Regioselective Polymer Consisting of Octahydrobifuranyl Unit

“…On the other hand, the diepoxide is a versatile monomer for cyclopolymerization leading to a gel-free polymer, in which 1,5- and 1,6-diepoxides are generally used as the monomer . For example, we reported that 1,2:4,5-dianhydropentitol and 1,2:5,6-dianhydrohexitol were regio- and stereoselectively cyclopolymerized to yield novel carbohydrate polymers of (1→5)-2,4-anhydropentitol and (1→6)-2,5-anhydrohexitol, respectively. , In addition, the cyclopolymerization of suitably molecular-designed α,ω-diepoxides except for the 1,5- and 1,6-ones was the facile synthetic method for poly(crown ether)s such as poly(dibenzo-19-crown-6) . In the present study, we attempted to develop the cyclopolymerization of diepoxides into the ring-opening and ring-forming polymerization of the triepoxide as shown in eq 1 in Scheme , based on the analogy of the tandem technology for the construction of tetrahydrofurans using oligo- and polyepoxide openings, e.g., the formation of the characteristic cyclic ether skeleton from the designed oligoepoxide (eq 2) and the synthesis of 2,5-poly(tetrahydrofuran)diyl from poly(butadiene epoxide) (eq 3) .…”