| 1. |
- Larsson, Kenneth, et al.
(författare)
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Methanolysis of galacturonic acid
- 1974
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Ingår i: Carbohydrate Research. ; 34, s. 323-329
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Tidskriftsartikel (refereegranskat)abstract
- Dimethyl acetals of galacturono-6,3-lactone and methyl galacturonate are formed during methanolysis of galacturonic acid. The products of methanolysis were studied by ion exchange and gas chromatography. Trimethylsilyl (TMS) derivatives were used in gas chromatography. Structure determinations were made from mass spectra of the TMS derivatives. The course of methanolysis was investigated by means of a gas chromatographic study of the composition of the reaction mixture as a function of time.
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| 2. |
- Petersson, Göran, 1941
(författare)
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Branched deoxyaldaric acids from alkaline degradation of carbohydrates: Structure determination by mass spectrometry of trimethylsilyl derivatives
- 1975
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Ingår i: Carbohydrate Research. ; 43, s. 1-8
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Tidskriftsartikel (refereegranskat)abstract
- The deoxyaldaric acids corresponding in structure to the 3-deoxy-2-C-(hydroxymethyl)aldonic (isosaccharinic) acids have been identified as products of treatment of various carbohydrates with alkali and oxygen-alkali. The structures of the acids were determined from the mass spectra of their Me3Si derivatives on the basis of previously known, specific fragmentation reactions. The g.l.c.-m.s. technique was used, and g.l.c. retention data are given. The identified species are 2-deoxy-3-C-(hydroxymethyl)tetraric, 3-deoxy-2-C-hydroxymethyl-erythro-pentaric, 3-deoxy-2-C-hydroxymethyl-threo-pentaric, 2-methyltartronic, 2-(2-hydroxyethyl)tartronic, and 2-(2,3-dihydroxypropyl)tartronic acids. Their formation from 4-O-substituted uronic and ulosonic acids is briefly discussed.
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| 3. |
- Petersson, Göran, 1941, et al.
(författare)
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Formation of 1,4-anhydro-3-deoxypentitol-2-carboxylic acids by alkaline degradation of cellulose
- 1976
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Ingår i: Acta Chemica Scandinavica B. ; 30, s. 27-30
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Tidskriftsartikel (refereegranskat)abstract
- An anhydroisosaccharinic acid obtained in large amounts by end-wise degradation of cellulose in alkaline media, and in small amounts in hydrolysates of cellulose, has been identified as a 1,4-anhydro-3-deoxypentitol-2-carboxylic acid (3-hydroxy-5-(hydroxymethyl)oxolane-3-carboxylic acid). Structural evidence was obtained by GC-MS studies of the compounds (as Me3Si derivatives) obtained on degradation of the acid to 1,4-anhydro-3-deoxypentitol by reduction of the methyl ester followed by periodate oxidation and borohydride reduction. In aqueous alkali, the acid is likely to be formed from a dicarbonyl precursor by benzilic acid rearrangement.
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| 4. |
- Abrahamsson, Jonas, 1954, et al.
(författare)
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The crystal structure of O-ethyl-S-(11-carboxyundecyl)dithiocarbonate
- 1976
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Ingår i: Acta Crystallographica Section B: Structural Science. - 0108-7681. ; 32:10, s. 2745-2749
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Tidskriftsartikel (refereegranskat)abstract
- O-Ethyl S-(I l-carboxyundecyl)dithiocarbonate (CJ5H~8S203) is triclinic (pT) with a=7·534, b=4·797, c=25·304 A, 0:=90·83, jJ=90·72 and y=79·71°. The bond distances and angles agree very well with those reported earlier for the homologue with a shorter carbon chain (C5). The conformations are also very similar in the two compounds. The ethyl end of one molecule just reaches S(2) of a neighbouring one. This results in a packing with only small regions of lateral hydrocarbon chain packing. The chain arrangement cannot be described by any known subcell.
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