Ring‐opening polymerization of carbohydrate‐derived dialkoxyoxolanes. Approaches to functionalized poly(oxytetramethylene)s

Abstract

A series of various cis-3,4-diacyloxy-and dialkyloxy-oxolanes (4 to 14) as well as the oxolanes 16 and 17 were prepared. Ring-opening polymerizations of the dialkyloxy derivatives 4,6, and 11 using the super-acids FS0,H and CF3S0,H led to novel functionalized poly[oxy(2,3-dialkyloxytetramethkene)]~. The reaction parameters were thoroughly studied, and optimum conditions lead to a DP, up to 35. All polyethers were fully assigned by polymer analytical procedures such as GPC, osmometry, 'H NMR spectroscopy and end group determination. In the case of the mixed benzyloxy methyloxy polymer 22, by subsequent hydrogenolysis a component with hydroxy functions was obtained. This procedure features a novel change of functionality in selectively derivatized polyethers originally derived from regrowing carbohydrate material.

Synthesis of Hyperbranched Carbohydrate Polymer by Ring-Opening Multibranching Polymerization of 1,4-Anhydroerythritol and 1,4-Anhydro-l-threitol

“…The extension of the polymerization time led to a decrease in M w,SLS as a comparison between runs 2 and 4. A similar result was reported in the ring-opening polymerization of 1,4-anhydro-2,3-di-O-methylerythritol (6a) and 1,4-anhydro-2,3-di-O-ethylerythritol using CF 3 SO 3 H and FSO 3 H. 11,12 In the polymerization of 1a using FSO 3 H as a catalyst, the M w,SLS was low as 1.0 × 10 4 , which should be related to the lower acidity of FSO 3 H (pK a ) -12.60) in contrast to CF 3 SO 3 H (pK a ) -19.12). 12 The M w,SLS values of the polymer (2b) prepared from 1b were lower than those of 2a; i.e., for the [1]/[CF 3 SO 3 H] molar ratio of 20 at 80 °C for 240 h, the M w,SLS value of 2b was 22.6 × 10 4 , while that of 2a was 51.0 × 10 4 .…”

“…13 C NMR (D2O) δ: 72.61 (C1 and C4), 71.08 (C2 and C3), 63.25 ppm (CH2OH, terminal). 11 and 1,4-anhydro-2,3di-O-methyl-L-threitol (6b) 12 were synthesized from erythritol and L-threitol, respectively, using a procedure similar to that reported by Thiem. 6a: Yield, 76.1%.…”

Synthesis of Hyperbranched Carbohydrate Polymers by Ring‐Opening Multibranching Polymerization of Anhydro Sugar

“…On the other hand, in the polymerization of 4a using FSO 3 H as a catalyst, the M w;SLS was as low as 1.0 Â 10 4 , which should be related to the lower acidity of FSO 3 H (pK a ¼ À12.6) in contrast to CF 3 SO 3 H (pK a ¼ À19.1). [54] The lower M w;SLS value (maximum 2.3 Â 10 5 ) of 5b compared to that of 5a should be caused by the difference in the ring strain effect between 4a and 4b; that is, the ring-opening reaction of the tetrahydrofuranyl ring in 4a proceeded more easily than that of 4b.…”

A Novel Polymeric Carbohydrate. Synthesis of (1→6)-2,5-Anhydro-d-glucitol by Regio- and Stereoselective Anionic Cyclopolymerization of 1,2:5,6-Dianhydro-d-mannitol

“…On the other hand, Thiem et al reported the synthesis of a polymeric carbohydrate by ring-opening polymerization of carbohydrate-derived dialkoxyoxolanes and 1,4:2,5: 3,6-trianhydro-D-mannitol. [10][11][12] Recently, we presented the cyclopolymerization of 1,2: 5,6-dianhydrohexitol as a new method for synthesizing polymeric carbohydrates. [13][14][15][16][17][18][19][20] 3,4-Di-O-alkyl substituted 1,2:5,6-dianhydro-D-mannitols and L-iditol were found to polymerize using cationic initiators, and the resulting polymers consisted of 2,5-anhydro-D-glucitols as the main repeating cyclized units, together with other cyclic units as minor components.…”

“…These polysaccharides are termed artificial polysaccharides. On the other hand, Thiem et al reported the synthesis of a polymeric carbohydrate by ring-opening polymerization of carbohydrate-derived dialkoxyoxolanes and 1,4:2,5:3,6-trianhydro- d -mannitol. − …”