A series of carbohydrate derivatives were prepared and their structural determination was made by NMR spectroscopy. The molecular structures of 1,2-<I>O</I>-isopropylidene-5-<I>O-p-</I>tosyl-α-D-xylofuranose (1) and 1,2-<I>O</I>-isopropylidene-3,5-di-<I>O</I>-<I>p-</I>tosyl-α-D-xylo-furanose (2) was determined by X-ray single-crystal diffraction. All the carbohydrate derivatives were used as precursors for the synthesis of stannylated carbohydrate derivatives. The synthesis of these stannylated carbohydrate derivatives were carried out using two methods: (i) the reaction of triphenylstannyl-lithium with derivatised and protected (or partially protected) carbohydrates and (ii) hydrostannation of alkenyl or allylic substituted carbohydrates using triphenyltin hydride. The solution structures of the triorganotin-carbohydrate derivatives were investigated by <SUP>1</SUP>H, <SUP>13</SUP>C and <SUP>119</SUP>Sn NMR spectroscopy. In solution all the triorganotin-carbohydrate derivatives were shown to contain four-coordinate tin atoms. Reactions of 1,4:3,6-dianhydro-2,5-di-<I>O-p</I>-tosyl-D-glucitol (3) with triphenylstannyl-lithium resulted in the synthesis of (2S,1'R)-(-)-2-[1-hydroxyl-2-(triphenylstannyl)ethyl]-2,5-dihydrofuran (4). Structural elucidation was performed by 1D and 2D NMR experiments as DEPT, HMQC, HMBC, <SUP>1</SUP>H/<SUP>1</SUP>H COSY, <SUP>1</SUP>H/<SUP>1</SUP>H Long-Range COSY and NOESY NMR experiments. (2R,1'R)-(+)-2-[1-hydroxyl-2-(triphenylstannyl)ethyl]-2,5-dihydrofuran (5) was obtained from reaction of 1,4:3,6-dianhydro-2,5-di-<I>O-p-</I>tosyl-D-mannitol (6) with triphenylstannyl-lithium. Complete assignment of the <SUP>119</SUP>Sn NMR spectra to the different tin atoms of methyl 2,3-di-<I>O</I>-[(dimethylphenylstannyl)methyl]-4,6-<I>O</I>-benzylidene-α-D-glucopyranoside (7) and methyl 2,3-di-<I>O-</I>[(triphenylstannyl)methyl]-4,6-<I>O-</I>benzylidene-α-D-glucopyranoside (8) was obtained from a sequence of single frequency tin decoupling experiments. Complete assignment of the <SUP>119</SUP>Sn NMR spectra for 3-[(triphenylstannyl)propyl] 5-deoxy-2,3-<I>O</I>-isopropylidene-5-C-triphenylstannyl-β-D-ribofuranoside (9) was aided with two dimensional correlation by application of the gradient-heteronuclear multiple quantum coherence method (gs-HMQC) for <SUP>1</SUP>H-<SUP>119</SUP>Sn correlation.
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:593379 |
| Date | January 1998 |
| Creators | Rufino, Helena Clara de Assuncao Rufino |
| Publisher | University of Aberdeen |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Source | http://digitool.abdn.ac.uk/R?func=search-advanced-go&find_code1=WSN&request1=AAIU530772 |
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