Mechanistic implications with respect to the formation of acylic and cyclic intermediates are discussed.doi:10.1016/S0008-6215(00)83779-9Frieder W. LichtenthalerGerd BambachElsevier LtdCarbohydrate Research
The key cyclopentane ring formation was achieved under the glycol cleavage reaction of methyl 3-O-benzyl-5,6-dideoxy-6-C-(methoxycarbonyl)-D-xylo-hepto-1,4-furanuronate, which was prepared by a seven-step sequence from D-glucose. The diastereomeric mixture of dimethyl 2-acetoxy-4-(form...
57,58are known to enhance the formation of pentoses. In fact, the most efficient ways in which such minerals are able to stabilise these sugars are with the furanoses that complex with these minerals due to the favourable dihedral angle of their hydroxyl groups...
The reactivity of the oxetane ring in 3,5-anhydro-1,2-O-cyclohexylidene-a-D-xylofuranose (1) was exemplified by its regiospecific nucleophilic opening. The action of concentrated hydrobromic or hydroiodic acid on 1 resulted in the exclusive formation of the 5-deoxy-5-halo derivatives, while ...
The key cyclopentane ring formation was achieved under the glycol cleavage reaction of methyl 3-O-benzyl-5,6-dideoxy-6-C-(methoxycarbo... K Tadano,K Hakuba,H Kimura,... - 《Journal of Organic Chemistry》 被引量: 15发表: 1989年 ChemInform Abstract: Syntheses of (1S,2S,3S,4R)- and ...
Their 2,3-di-0-methyl derivatives show a n even stronger preference for a five membered ring structure in both solvents. This is most li~arl344511 33 65 ca. 15s 38 ca. *The measurements were made over prolonged periods (several weeks) until no furtherchange was evident. tBased o n ...
In particular, absence of the UDP-Gal transport, which was confirmed by the inability of glfB to complement the CHO cell line Lec8, indicates that the transporter is able to discern the ring conformation of the monosaccharide. Vice versa, our data show that the human UDP-Gal transporter ...
The formation of 4-thio-L-arabinofuranose derivatives by ring contraction of 1,2-O-isopropylidene-3,4-di-O-methanesulphonyl-5-thio-?-D-xylopyranose O-methyl-β-D-fructopyranose (1) reacts with n-butyllithium to give 1,2;4,5-di-O-isopropylidene-3-O-methyl-1,2-didehydro-D-arabino-...
The convenient formation of the 1,2- cis connected - D -mannofuranosides and -pyranosides is explained by intramolecular complexation in the 1- O -metallated species. The easily accessible D -glyceryl- D -mannopyranosides 8 and 9 are important intermediates for glycolipids and glycoconjugates...
However, application of the same reaction conditions to 1 led to the predominant formation of a cyclic 3,5-anhydro derivative. In contrast, the reaction of hydrazoic acid with 1 afforded 5-azido-5-deoxy-1,2-O-isopropylidene-α-D-xylofuranose besides formerly unknown 5-azido-3,5-dideoxy-1...