Synthesis of C-linked analogues of β-d-galactopyranosyl-(1→3)-d-galactopyranosides and of β-d-galactopyranosyl-(1→3)-d-galactal

Synthesis of chemical tools to improve water solubility and promote the delivery of salinomycin to cancer cells

“…2B). A known aldehyde 4 (25,(29)(30)(31)(32)(33)(34)(35)(36)(37) was treated under Henry reaction conditions (38) with nitromethane, in the presence of ammonium acetate to form the dehydrated product 5. The crude product 5 was subsequently treated with sodium borohydride in the presence of double distilled water and methanol for complete reduction in order to produce the amine form 6, which was treated with trifluoromethanesulfonyl azide in order to convert it to the azido sugar 7.…”

Stereoselective preparation of four 3-C-mannosylated d- and l-glucals from a single starting compound

“…20 The same epoxidation of 3-C-glycosylated galactal, i.e., 4,6-di-O-benzyl-3-C-[(1R)-1,3,4,5, 7-penta-O-benzyl-2,6-anhydro-D-glycero-L-manno-heptitol-1-C-yl]-3-deoxy-D-galactal, took place predominantly from the b-face under formation of methyl 4,6-di-O-benzyl-1,3-C-[(1R)-1,3,4,5,7-penta-Obenzyl-2,6-anhydro-D-glycero-L-manno-heptitol-1-C-yl]-3-deoxya-D-talo-pyranoside as the principal reaction product. 21 We performed this simple epoxidation with glucal 1 and found that the reaction also proceeded preferentially from the b-face and that stereoselectivity of the epoxidation is practically the same as in the case of the C-glycosylated galactal. 21 The epoxidation afforded a mixture of two methyl glycosides 33 and 34, which were easily separable by chromatography on silica gel (Scheme 5).…”

“…21 We performed this simple epoxidation with glucal 1 and found that the reaction also proceeded preferentially from the b-face and that stereoselectivity of the epoxidation is practically the same as in the case of the C-glycosylated galactal. 21 The epoxidation afforded a mixture of two methyl glycosides 33 and 34, which were easily separable by chromatography on silica gel (Scheme 5). The major product 33 was isolated chromatographically in 56% yield, and the minor product 34 was isolated in 20% yield.…”

C-Glycopyranosyl aldehydes: emerging chiral synthons in organic synthesis

“…Some of them play important roles in biological systems, for instance, glycoconjugate 125 is a potent inhibitor of ice recrystallization and could protect embryonic liver cells from cryo-injury; 46 the acyl- and benzyl- C -β- d -glucosides (126 and 127) work as glucose uptake promotor; 58 C -mannosides analogues (128a–b) block uropathogenic Escherichia coli from colonizing the lower urinary tract; 59 C -glycosides 129a–c were determined by ELISA of a blood sample obtained from mice stimulated by a 1 μg injection of glycolipid in the buffer. It was found that E -isomer 129b is superior to Z -isomer 129c as a ligand for CD1d/NKT immunity pathway; 48 C -linked galactosphingo lipid analogue (130) blocks the interaction of HIV-1 gp120 with GalCer; 60 C -linked disaccharide analogue (131a) of TF epitope induces a strong immune response in mice, which imparts it a possibility to be developed as a therapeutic vaccine; 61 C -linked disaccharide (132a) mimics O -β- d -galactopyranosyl-(1–3)- d -galactopyranosidesand proved to be a suitable agent for O -glycosidation and construction of glycoconjugates; 62 carbohydrate amino acids mimetic (133) shows in vivo stability towards α-galactosidase enzyme and might function as glycosidase inhibitor( Fig. 4 ).…”

“…Demange et al 62 reported the synthesis of C -linked disaccharides, which mimics O -β- d -galactopyranosyl-(1→3)- d -galactopyranosides starting from C -galactopyranosyl aldehyde. Three C -linked disaccharides 132a, 132b, and 132c were synthesized, out of which 132a was found to be a suitable agent for O -glycosidation and for the construction of conjugates ( Scheme 37 ).…”