Mono‐ und Dioxetane von 2,5‐Anhydroalditolen, Synthesen und Reaktionen

Köll, Peter; Oelting, Michael

doi:10.1002/jlac.198719870309

Cited by 14 publications

References 42 publications

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ChemInform Abstract: Mono‐ and Dioxetanes of 2,5‐Anhydroalditols, Syntheses and Reactions.

Koell¹,

Oelting²

1987

ChemInform

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293ChemInform Abstract The tosylates (Ib) (from (Ia)), (Ic), or (Id) give the mono oxetanes (IIa), (IIb), or (IIc) on treatment with Na-methylate; use of an excess of methylate produces the dioxetane (III) exclusively. With some modifications, the compounds (IV), (Va), (Vb), and (VI) (from (Vb)) are similarly prepared. The treatment of the tosylate (VII) with Na methylate, however, leads to the dianhydro L-arabinitol (VIII). A series of reactions of the mono-and dioxetanes prepared are described. Thus, for instance, the compounds (IXa), (IXb), or (X) are obtained by reaction of HCl with (IIc), (III), or (IV), respectively. In the presence of MeOH, the methoxy compound (XI) is formed from (IIc). The reduction product (XII) is obtained from (III). Further, a synthesis of the "double-headed" muscarin relative (XIV) with ido configuration can be accomplished.

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ChemInform Abstract: Mono‐ and Dioxetanes of 2,5‐Anhydroalditols, Syntheses and Reactions.

Koell¹,

Oelting²

1987

ChemInform

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Synthesis and ring‐opening polymerization of 1,4:2,5:3,6‐trianhydro‐D‐mannitol and structure studies by MNDO calculations

1991

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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

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Chemical ionization mass spectra of the stereoisomeric 1,5‐anhydropentofuranoses, 1,6‐anhydrohexofuranoses and 1,6 : 3,5‐dianhydrohexofuranoses

Metzger¹,

Schwarting²,

Köll³

et al. 1992

Org. Mass Spectrom.

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The isobutane and methane direct chemical ionization (DCI) mass spectra of mono-and dianhydrosugars are substantially influenced by their stereochemistry at temperatures of 150-250°C. The best results are obtained under isobutane Ci at 200 or 250°C. 1,6 : 3,5-Dianhydrogulofuranose gives proton-bridge stabilized MH* ions and fewer fragment ions compared with its ido epimer. TJ e four diastereomeric 1,5-anhydropentofuranoses show increased MH+ and MzH+ abundance for the fyxo and rib0 isomers with cis-l,2diol sites capable of proton bridging. The xyfo isomer gives a dominant IM -OH1 + ion. All isomers, but especially xyfo and ribo, give abundant [C,H,O,] + skeleton cleavage ions. They are attributed to an RDA fragmentation of pyranoglycosyl-type MH+ ions. The eight diastereomeric 1,6-anhydrohexofuranoses with endolexo coofigured trio1 structures show very characteristic MH+ abundances (4-41% Z). They parallel the amount of proton solvation in cisdiol sites of the isomers &hco < id0 < altro < gufo < galacto < tufo < all0 < manno). The [ M -OH 1 + ion abundances (15-47% Z) are also very characteristic @fact0 < talo < manno < altro g alfo < gfuco < id0 g gulo). They reflect the possible H,O or C4H,0H loss from the MH+ and IM * C4H,I + ions, respectively, with formation of protonated 1,6:3,5-and 1,6 : 2,5-dianhydr&exofuranose species; the slightly flattened C (5) site of M might favour the departure of the S O H group In addition, there are especially high abundances of skeleton fragment ions, 15% Z IMH -HCOOHl+, 10% Z IM -OH -H,O -CH,OI+ and 42% Z 1M -OH -C,H,O,I+, for the ido, gafacto and gfuco isomers, respectively. Received

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Mono‐ und Dioxetane von 2,5‐Anhydroalditolen, Synthesen und Reaktionen

Cited by 14 publications

References 42 publications

ChemInform Abstract: Mono‐ and Dioxetanes of 2,5‐Anhydroalditols, Syntheses and Reactions.

ChemInform Abstract: Mono‐ and Dioxetanes of 2,5‐Anhydroalditols, Syntheses and Reactions.

Synthesis and ring‐opening polymerization of 1,4:2,5:3,6‐trianhydro‐D‐mannitol and structure studies by MNDO calculations

Chemical ionization mass spectra of the stereoisomeric 1,5‐anhydropentofuranoses, 1,6‐anhydrohexofuranoses and 1,6 : 3,5‐dianhydrohexofuranoses

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