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Application of the oxo reaction to various carbohydrate derivatives

University of British Columbia

3,4,6-Tri-0-acetyl-D-glucal (1) reacted with carbon monoxide and hydrogen in the presence of dicobalt octacarbonyl to yield a mixture of two epimeric anhydrodeoxyheptitols, namely, 4,5,7-tri-0-acetyl-2,6-anhydro-3-deoxy-D-manno-heptitol (2) and 4,5,7-tri-0-acetyl-2,6-anhydro-3-deoxy-D-gluco-heptitol (3). De-0-acetylation of the mixture, followed by chromatographic separation, yielded 2,6-anhydro-3-deoxy-D-manno-heptitol (4) and 2,6-anhydro-3-deoxy-D-gluco-heptitol (5). Compounds (4) and (5) were oxidised with periodate to yield dialdehydes which on reduction with sodium borohydride afforded enantiomeric tetrol ethers. Reaction of 3,4,6-tri-0-acetyl-D-glucal (1) with carbon monoxide and deuterium, followed by de-0-acetylation and chromatographic separation gave 2,6-anhydro-5-deoxy-D-manno-heptitol-1,1,3-²H3(cis)(6) and 2,6-anhydro-3-deoxy-D-gluco-heptitol-1, 1,3-²H3(cis) (7) . Examination of the proton magnetic resonance spectra of the normal (4,5) and deuterated anhydrodeoxy heptitols (6,7) revealed their structures and showed that cis-addition of carbon monoxide and hydrogen to the double bond of (1) had taken place. Reaction of the mixture of partially acetylated heptitols (2) and (3) with p-toluenesulphonyl chloride followed by fractional crystallisation of the products gave pure 4,5,7-tri-0-acetyl-2,6-anhydro-3-deoxy-1-0-(p-toluenesul-phonyl)-D-gluco-heptitol (8). Similarly,, the mixture of (2) and (3) reacted with p-bromobenzenesulphonyl bromide to give 4,5, 7-tri-0-acetyl-2,6-anhydro-1-0-(p-bromobenzenesulphonyl)-3-deoxy-D-gluco-heptitol (11), the structure of which was confirmed by X-ray structure analysis by A. Camerman and J. Trotter. Therefore, the absolute structures of compounds (4) and (5) were ascertained. Compounds (8) and (11) were converted to (5) by a series of reactions. Comparison of the exchange reaction of sodium iodide with 4,5,7-tri- 0-acetyl-2,6-anhydro-3-deoxy-1-0-(p-toluenesulphonyl)-D-gluco-heptitol (8) and with 4,5,7-tri-0-acetyl-2,6-anhydro-3-deoxy-1-0-(p-toluenesulphonyl)-D-manno-heptitol (14) revealed that the equatorial primary p-toluenesulphonoxy group of (8) was exchanged more readily than that of (14). The hydroformylation of (1) yielded two enantiomeric aldehydes (16a, 16b) which were separated chromatographically via their 2,4-dinitrophenyl-hydrazones (16b) and (17b). Both (16b) and (17b) were degraded to (4) and (5), respectively. 3,4-Di-0-acetyl-D-arabinal (18) reacted with carbon monoxide and hydrogen in the presence of dicobalt octacarbonyl to yield, upon de-0-acetylation and chromatographic separation, a mixture of two epimeric anhydro-deoxyhexitols, namely, 1,5-anhydro-4-deoxy-L-ribo-hexitol (21) and 1,5-anhydro-4-deoxy-D-lyxo-hexitol (22). Compounds (21) and (22) were converted into enantiomeric 2-deoxy-3-0-(2-hydroxyethyl)-L-glycero-tetritol (23) and 2-deoxy-3-0-(2-hydroxyethyl)-D-glycero-tetritol (24). Compound (23) was identical to an authentic sample of 2-deoxy-3-0-(2-hydroxyethyl)-L-glycero-tetritol. 1,2,4,6-Tetra-0-acetyl-3-deoxy-α-D-erythro-hex-2-enopyranose (29) reacted with carbon monoxide and hydrogen in the presence of dicobalt octacarbonyl to yield 1,2,3¹,4,6-penta-0-acetyl-3-deoxy-3-C-(hydroxymethyl)-α-D-gluco-pyranose (31) besides hydrogenolysed hydrohydroxymethylated products, a similar reaction of (29) with deuterium instead of hydrogen gave 1,2,3¹,4,6-penta-0-acetyl-3-deoxy-3-C- (hydroxymethyl) -α-D-gluco-pyranose-2,3¹,3¹ -²H3 (cis) (33). The structures of (31) and (33) were established by p.m.r. spectroscopy. 2,3,4,6-Tetra-0-acetyl-α-D-glucosyl bromide (26) reacted with sodium tetracarbonylcobaltate under compressed carbon monoxide followed by treatment with triphenylphosphine to afford 2,3,4,6-tetra-0-acetyl-β-D-glucosyl tri-carbonyl triphenylphosphine cobaltate (39) and 3,4,5,7-tetra-0-acetyl-2,6- anhydro-D-glycero-D-gulo-heptosoyl tricarbonyl triphenylphosphine cobaltate (41). Reduction of. (39) and (41) with sodium borohydride followed by acetylation gave 2,3,4,6-tetra-0-acetyl-1,5-anhydro-D-glucitol (40) and 1,3,4,5,7-penta-0-acetyl-2,6-anhydro-D-glycero-D-gulo-heptitol (42). Both (40) and (42) were compared with authentic samples and shown to be the same.

Text

2011-10-19

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http://hdl.handle.net/2429/38083

Chemistry

University of British Columbia

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