Cyclopolymerization of diepoxides

Abstract

SynopsisThe moriomer 1,2,5,6-diepoxyhexane can be polymerized by a variety of catalysts to afford a polymer which has tetrahydropyran recurring units as a result of a cyclopolyrnerization mechanism. A phosphorus pentafluoride-water catalyst system gives soluble polymer with inherent viscosities as high as 0.37. The polymerization rates, conversions, and polymer molecular weights are affected both by catalyst to monomer ratio and the amount of water present. A diethyleinc-water catalyst system gives a higher molecular weight polymer with very limited solubility, the soluble portion of which has an inherent viscosity of 0.45. In contrast, 1,2,4,5diepoxypentane polymerizes to a completely insoluble polymer in all catalyst systems employed. Samples of poly-1,2,5,6-diepoxyhexane prepared with the diethylainc-water catalyst show a higher degree of crystallinity than those snniples prepared with the phosphorus pentafluoride-water catalyst, as demonstrated by x-ray patterns and differential thermal analyses.

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

“…1,2:5,6-Diepoxyhexane and 1,2epoxyethylbenzene capable of forming 5-or 6-membered rings were polymerized to form polymers consisting of tetrahydropyran or tetrahydrofuran recurring units, depending upon the conditions. [27][28][29][30] The cationic cyclopolymerization of 1 mainly formed 5-membered rings, (1f6)-bonded 2,5-anhydro-D-glucitol units. Figures 1 and 2 show the 1 H and 13 C NMR spectra of polymer 3 prepared by the anionic polymerization of 1, respectively.…”

Regio- and Stereospecificity in Cationic Cyclopolymerization of 1,2:5,6-Dianhydro-D-mannitols and Synthesis of Poly[(1.fwdarw.6)-2,5-anhydro-3,4-di-O-ethyl-D-glucitol]

“…Wiggins and Wood reported that l,2:5,6-diepoxyhexane reacted with water to form the corresponding 2,5-bis(hydromethyl)tetrahydrofuran.1 Stille et al, Bauer et al., and Aso et al reported that the diepoxide was polymerized to produce soluble polymers consisting of tetrahydropyran or tetrahydrofuran units as the cyclic constitutional units depending on the catalyst used. [2][3][4] In a previous study, (2ñ,18I? )-(-)-and (2S, 18S)-(+)-5,6:14,15-dibenzo-l,2:18,19-diepoxy-4,7,10,-13,16-pentaoxanonadeca-5,14-diene polymerized regioand stereospecifically to yield poly[(JZ^R)-dibenzo-19crown-6] and poly[(S,S)-dibenzo-19-crown-6], respectively, which exhibited a chiral recognition ability toward racemic -amino acids.…”

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

“…Thus pentitol, which is a commercially available sugar alcohol after hexitol, may be an appropriate raw material for a dianhydro monomer. So far, Stille et al reported the cyclopolymerization of achiral diepoxides, in which 1,2 : 4,5-diepoxypentane produced only an insoluble polymer, although 1,2 : 5,6-diepoxyhexane was polymerized using cationic and anionic initiators to produce organic-solvent soluble polymers consisting of the 5-and 6-membered cyclic repeating units 15) . In this paper, we report the successful cyclopolymerization of 1,2 : 4,5-dianhydro-3-O-methyl-xylitol (1) and the production of a novel polycarbohydrate containing 1,4-anhydro-3-Omethyl-DL-arabinitol as repeating units (Scheme 1).…”