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Synthesis of Some New 6,7-Unsaturated Octuronates From 5-O-tert-Butyldimethylsilyl-1,2-O-Isopropylidene-α-D-gluco-and β-L-ido-Hexodialdose and their Transformation into Octoses and Octitols via Osmylation
Titel:
Synthesis of Some New 6,7-Unsaturated Octuronates From 5-O-tert-Butyldimethylsilyl-1,2-O-Isopropylidene-α-D-gluco-and β-L-ido-Hexodialdose and their Transformation into Octoses and Octitols via Osmylation
Auteur:
Berger, A. Dax, K. Gradnig, G. Grassberger, V. Stutz, A. E.
Verschenen in:
Journal of carbohydrate chemistry
Paginering:
Jaargang 11 (1992) nr. 3 pagina's 217-241
Jaar:
1992-04-01
Inhoud:
Carbon chain extensions of 5-O-tert-butyldimethylsilyl-1,2-O-isopropylidene-α-D-gluco-and β-L-ido-hexodialdose with ethoxycarbonylmethylenetriphenylphosphorane or triethyl phosphonoacetate gave the corresponding α,β-unsaturated octuronic esters, the (E)/(Z)-ratios of which strongly depending on the reagent used as well as the starting material. After conventional reduction of the ester moieties the corresponding O-acetyl protected allylic alcohols were subjected to osmylation leading to the respective 1,2-O-isopropylidene protected octoses, which were subsequently converted to some previously unreported octitols. Unambiguous structure proofs, demonstrating the validity of Kishi's empirical rule for the stereochemical outcome of the osmylation reactions reported, were obtained from the NMR spectroscopic features of these products as well as regiospecific chemical degradations to corresponding known heptitols.
Uitgever:
Taylor & Francis
Bronbestand:
Elektronische Wetenschappelijke Tijdschriften
Details van artikel 208 van 252 gevonden artikelen