Die Disterecmeren Methylhexofuranosidurono-6,3-Lactone, Synthese und Konformationsanalyse Mittels Nmr-Spektroskopie
Titel:
Die Disterecmeren Methylhexofuranosidurono-6,3-Lactone, Synthese und Konformationsanalyse Mittels Nmr-Spektroskopie
Auteur:
Albert, Rain Dax, Karl Stutz, Arnold E. Zekoll, Haim Sterk, Heinz
Verschenen in:
Journal of carbohydrate chemistry
Paginering:
Jaargang 7 (1988) nr. 3 pagina's 537-554
Jaar:
1988-09-01
Inhoud:
Starting from D-gluco-and D-mannofuranurono-6,3-lactone, respectively, one enantiomer each of the diastermeric methyl 2-O-thoxy-carbonylhexofuranosidurnon-6,3-lactones was prepared by making use of regioselective esterification and configurational inversion at C-5 via triflates. Analysis of the proton-proton and proton-carbon 13 couplings revealed the conformation of the furanoid ring to be strongly govern by the anomeric effect since pseudoequatorial position of the anomeric proton was found in all diasteromers except those with α-D-manno-and B-L-gulo-configuration where the unfavorable cis-orientation of 0-4/0-5 and/or 0-2/0-3 counteracts successfully.