Synthesis of novel HIV-1 protease inhibitors based on carbohydrate scaffolds

Direct Experimental Evidence for the High Chemical Reactivity of α‐ and β‐Xylopyranosides Adopting a 2,5B Conformation in Glycosyl Transfer

“…The orthogonally protected sugar 1 [21] was selected as a suitable starting material. Because installation of the "vinylic arm" at C-2 by addition of vinyl magnesium bromide onto a methyl b-2-uloside would predominantly give the wrong manno-like stereoisomer, [22] sugar 1 was oxidized and olefinated at the 2-position to afford the exomethylenic derivative 2 [23] (65 % yield over two steps).…”

Non‐Glycosidically Linked Pseudodisaccharides: Thioethers, Sulfoxides, Sulfones, Ethers, Selenoethers, and Their Binding to Lectins

“…Related approaches have been used for the synthesis of thiooligosaccharides; carbohydrate sulfonates have been displaced either by thioacetate to introduce sulfur, or by an anomeric thiol for thiodisaccharide formation. [15] We converted some partially protected carbohydrates 1-6 [16][17][18][19][20][21] to their triflates 8-12 [22][23][24][25][26] or mesylate (7). In many cases, heating the sulfonates with potassium thioacetate in DMF gave a clean and high-yielding conversion to the thioacetates 13-17 with inversion of configuration (Scheme 1).…”

“…Alcohol 3 [18] (1.0 g, 2.7 mmol) was converted with pyridine (0.54 mL, 6.7 mmol) and triflic anhydride (0.55 mL, 3.4 mmol) in CH 2 Cl 2 (10 mL) by the same procedure as described for compound 8, into the crude triflate 9, [23] which was used without further purification, or purified by flash column chromatography (toluene/ EtOAc, 5:1, 1 % Et 3 N).…”

Synthesis of monodeoxy and mono-O-methyl congeners of methyl β-d-mannopyranosyl-(1→2)-β-d-mannopyranoside for epitope mapping of anti-Candida albicans antibodies

“…Reductive benzylidene acetal opening of methyl 3-O-benzyl-4,6-O-benzylidene-b-D-glucopyranoside (37) 15 under anhydrous conditions with BH 3 ÁTHF and dibutylboron triflate 22 gave diol 38 in 83% yield (Scheme 5). Controlled reaction of the C-6 primary hydroxyl with methanesulfonyl chloride in pyridine gave intermediate 39 (66% yield).…”