Synthesis of 4-(4,6-di-O-benzyl-2,3-dideoxy-β-d-erythro-hex-2-enopyranosyl)pyrazoles from 3,4,6-tri-O-acetyl-d-glucal

Ferrier–Nicholas Cations from C‐3‐Alkynylglycals: Access to C‐3‐Branched Allylic Glycosides and Ring‐Opening Derivatives

“…Hex‐2‐enopyranoses or pseudoglycals (e.g., 3 ) have been used extensively in carbohydrate chemistry, and – arguably – they represent one of the most appealing classes of carbohydrate derivatives used in synthesis , . They have been used in the preparation of a variety of natural products, including antibiotics, nucleosides, glycopeptides, and modified carbohydrates . Furthermore, the olefin moiety in 2,3‐unsaturated glycosides can be readily functionalized to give access to 2‐deoxy, 2,3‐dideoxy, and other highly deoxygenated oligosaccharides.…”

Substrate-Controlled Direct α-Stereoselective Synthesis of Deoxyglycosides from Glycals Using B(C6F5)3 as Catalyst

“…Following the general glycosylation procedure, donor 1a (50 mg, 0.18 mmol), B(C 6 F 5 ) 3 (5 mg 0.01 mmol), and acceptor 2h (36 mg, 0.14 mmol) to afford following purification by silica gel column chromatography (Hexane:EtOAc, 7:1 to 3:1) 3h as a colorless oil (44 mg, 67%). 1 H NMR (500 MHz, CDCl 3 ) δ 6.16 (ddd, J = 10.0, 5.5, 1.1 Hz, 1H, H-2'), 6.09−5.99 (m, 1H, H-3′), 5.90 (d,J = 3.6 Hz,1H,1H,, 5.04 (dt, J = 5.5, 2.8 Hz, 1H, H-4′), 4.63 (d,J = 3.6 Hz,1H,3H,2H,2H,, 3.99 (dd, J = 8.6, 5.1 Hz, 1H, H-6b), 2.13 (s, 3H), 2.10 (s, 3H), 1.52 (s, 3H), 1.42 (s, 3H), 1.33 (d,J = 4.1 Hz,6H). 13 4,.…”

Synthesis and Cytotoxicity of 2,3-Enopyranosyl C-Linked Conjugates of Genistein

“…2,3-Unsaturated- O -glycosides are easily available chiral intermediates in the synthesis of biologically active compounds such as glycopeptide building blocks, oligosaccharides, and modified carbohydrates [7,8,9,10,11]. They have also been employed in the synthesis of some important antibiotics and nucleosides [12,13,14]. Our recent study indicates that introducing unsaturation into the pyranoside ring of flavonoid O-glycosides and glycoconjugates brings about pronounced changes in their biological activity profiles [15,16,17].…”