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A total asymmetric synthesis of the polyol subunit of the polyene macrolide antibiotic RK-397 was developed through the stereoselective functionalization of (1R,1’S,6S,6’R)-3,3’-methylenebis(cyclohept-3-ene-1,6-diol). The pathway generates a large variety ...
Glycoproteins and glycolipids are major components of the outer surface of mammalian cells. Their carbohydrate moieties, which are directed into the outer environment, serve as ligands for receptor proteins, such as lectins, pathogen proteins and antibodie ...
The anomeric effect, originally defined as the preference of an electronegative substituent at the anomeric position of pyranosides to stand in an axial rather than an equatorial position, results from the combination of multiple steric, stereoelectronic a ...
Many natural products of biological interest contain [6,5]- and [6,6]-spiroketal moieties that can adopt various configurations, benefiting or not from anomeric conformation stabilizing effects. The spiroketal fragments are often important for the biologic ...
For more than thirty years there has been a high demand for glucose measuring devices to replace the finger pricking methods and to improve the life quality of diabetics. Three approaches are possible, electrochemical, electromagnetic (including optical), ...
A tinglucal tributyl[4,6-O-bis(t-butyl)silylidene-3-O-tris(isopropyl)silyl]tin 7 and a triflate derived from isolevoglucosenone (1R,4R,5R)-4-benzyloxy-6,8-dioxabicyclo[3.2.1]oct-2-en-2-yl trifluoromethanesulfonate 10 undergo the carbonylative Stille conden ...
In the first part, we described the synthesis of C-(1'→1) and C-(1'→4) disaccharide precursors, which are readily obtained via the carbonylative Stille coupling of glucal and isolevoglucosenone derivatives. Tin glycals and triflates, derived from isolevogl ...
The Oshima-Nozaki (Et2AlI) condensation of isolevoglucosenone (4) with 2,6-anhydro-3,4,5,7-tetra-O-benzyl-D-glycero-D-gulo-heptose (5) gave an enone 6 that was converted with high stereoselectivity to 3-C-[(IR)-2,6-anhydro-D-glycero-D-gulo-heptitol-1-C-yl] ...
An expeditious and efficient synthesis of new enantiopure polyhydroxylated seven- and eight-membered carbocycles is described starting from 2,3.5-tri-O-benzyl-D-arabinose. The key cyclization step involves ring closing metathesis of 1,8- and 1,9-dienes usi ...
The reactivity of (E)- and (Z)-1-fluorobuta-1,3-diene ((E)- and (Z)-11), 2-fluorobutadiene (12). (E)and (Z)-1-(fluoromethylidene)-2-methylidenecyclohexane ((E)- and (Z)-13) toward SO2 has been explored and compared with that of (Z)- and (E)-1-(fluoromethyl ...
