Guanidine/guanidinium nitrate; a mild and selective O-deacetylation reagent that leaves the N-Troc group intact

Synthesis of the TrifucosylatedN-Linked Hexasaccharide of a Glycoprotein fromHaemonchus contortus

“…Diol 2 was prepared from 6 [12] by O-deacetylation with guanidine/guanidinium nitrate [13] (G/GHNO 3 ) followed by acetalization to form 7, which was then reductively opened to generate the acceptor with two free hydroxyl groups. The distal GlcNAc residue 3, which was to be used first as a glycosyl donor and then as the terminal part of the acceptor in the following step, was made from 8 [14] by O-acetylation.…”

“…After O-deacetylation and purification by gel permeation chromatography compound 1 was isolated in 83% yield. The anomeric region of the 1 H, 13 C-HSQC spectrum of 1 is shown in Figure 2. That 8 Hz.…”

Synthesis of a-O- and a-S-Glycosphingolipids Related to Sphingomonous cell Wall Antigens Using Anomerisation

“…This was achieved in two steps. The methyl ester was removed using LiI in EtOAc [34], and a subsequent reaction with guanidine and guanidinium nitrate [35] in methanol-dichloromethane gave 8 and 9. Scheme 6.…”

Structural analogues of diosgenyl saponins: Synthesis and anticancer activity

“…Compound 15 was treated with guanidinium nitrate-sodium methoxide at room temperature to give the Odeacetylated product 16 in 90% yield leaving the N-Troc group intact. 21 Selective benzoylation of 16 with 2.1 equiv of benzoyl chloride in the presence of DMAP at À40°C gave 3,6-di-O-benzoylated product 17 in 69% yield. The structure of 17 was confirmed by 1 H-1 H COSY 2D NMR spectroscopy.…”