Base-catalyzed intramolecular nucleophilic substitution of various dianhydrosorbitol derivatives (2,4, or 6) led to formation of trianhydromannitol(7), a tricyclic system of three interlinked oxolane rings. By treatment with trifluoromethanesulfonic acid, ring-opening reactions were achievedto give oligomeric soluble material with a number-average degree of polymerization DP, = 5 -10. Molecular weights were determined by GPC, and by desorptive chemical ionization (DCI) with ammonia a molecular weight assignment gave information on the degree of crosslinking. A complex but consistent picture allows to explain the propagation reactions of protonated trianhydromannitols 8 and 9, and further reactions of the protonated intermediates 13-15 to result in crosslinked products 16 and 17. By semiempirical quantum chemical calculations, geometries, energies and charge distributions of 7 as well as its protonated species were obtained. This allowed comparisons with their chemical reactivity and ring-opening specificity.Syntheses of monomeric compounds were followed by TLC on silica gel foils GF,,, (Merck). Detection was done by UV and/or spraying with 10% ethanolic sulfuric acid with subsequent heating to about 300°C. For column chromatography silica gel 60 (70-230 mesh, Merck) was used, and 'H NMR (300 MHz) and I3C NMR (75,46 MHz) were elaborated on a Bruker spectrometer WM 300.The number-average molecular weight D,, was determined using a Knauer vapor pressure osmometer. Selective polymer fraction_s of poly(oxy-2,3-diethoxytetramethylene) were isolated and cleaned by GPC and their exact M,, measured by vapor pressure osmometry. These values served as a basis for the calibration curve which was used to establish the weight-average molecular weight a, by GPC. GPC was performed using the combined instruments: pump (Knauer, analytical), differential refractometer type 98,00 (Knauer), integrator (Spectra-Physics). The molecular weights were determined by use of the Winner system and the GPC software (Spectra-Physics) on a XT-PC (Epson).For mass spectra and GC/MS measurements the equipment CH-7A (Varian), MAT and MAT 8230 (Finnigan-MAT GC/MS coupling, 70 eV) were applied and desorptive chemical ionization (DCI) spectra were obtained with MAT 8230 (Finnigan-MAT) using ammonia as reactant gas. Syntheses

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.

By ring-opening copolymerization of 1,4-anhydr0-2,3-di-O-ethyl-~-erythritol (cis-3,4-diethoxyoxolane, 1) or 1,4:2,5:3,6-trianhydro-~-mannitol (3) with tetrahydrofuran carbohydratecontaining copolyether polyols were obtained. Using trifluoromethanesulfonic acid as catalyst the molecular weights were in a range from M , = 13OOO up to 25000 with about 10% of carbohydrate constituent. The novel copolyethers were studied by polymer analytical procedures, their structures 4 and 5 tentatively assigned and compared to the homopolymerization products of the monomers. The present procedure features an approach to novel partially functionalized high molecular weight copolymer polyols based on carbohydrate-derived materials.

Bei der Umsetzung von 1,4:3,6‐Dianhydro‐D‐sorbit mit Basen und α,ω‐Dihalogenalkanen werden Mono‐ und Dialkylderivate erhalten, mit trans‐1,4‐Dichlor‐2‐buten lassen sich Oligomere bis zum Heptamer isolieren und strukturell zuordnen. Ringöffnende Polymerisationen von substituierten Tetrahydrofuranen mit Supersäuren führen im Falle der 1,4‐Anhydro‐2,3‐di‐O‐alkyl‐D‐erythrite zu funktionalisierten Poly(oxytetramethylenen). Durch detaillierte Studien der Reaktionsparameter lassen sich optimierte Umsetzungsbedingungen erzielen, und mit polymeranalytischen Untersuchungen werden die linearen Strukturen der Polyether nachgewiesen.