Treatment of methyl 5-acetamido-2,4,7,8,9-penta-O-acetyl-3,5-dideoxy-β-d-glycero-d-gala cto-2-nonulopyranosonate (1) severally with thiophenol, phenylmethanethiol, and ethanethiol in the presence of boron trifluoride etherate gave the corresponding 2-thio-β-glycosides 3-5. Treatment of methyl (5-acetamido-4,7,8,9-tetra-O-acetyl-3,5-dideoxy-β-d-glycero- d-galacto-2-nonulopyranosyl chloride)onate (2) severally with thiophenol in the presence of N,N-di-isopropylethylamine, O-ethyl S-potassium dithiocarbonate, and O-ethyl S-potassium thiocarbonate gave the corresponding 2-thio-α-glycosides 7, 10, and 11, of which 10 was converted into the ethyl 2-thio-α-glycoside 9 on heating with N,N-dimethylformamide-sodium iodide. The phenyl 2-thioglycosides 3 and 7 were converted into the corresponding sulfones. © 1989.
STEREOSELECTIVE SYNTHESIS OF 2-THIOGLYCOSIDES OF N-ACETYLNEURAMINIC ACID
MARRA, Alberto;
1989
Abstract
Treatment of methyl 5-acetamido-2,4,7,8,9-penta-O-acetyl-3,5-dideoxy-β-d-glycero-d-gala cto-2-nonulopyranosonate (1) severally with thiophenol, phenylmethanethiol, and ethanethiol in the presence of boron trifluoride etherate gave the corresponding 2-thio-β-glycosides 3-5. Treatment of methyl (5-acetamido-4,7,8,9-tetra-O-acetyl-3,5-dideoxy-β-d-glycero- d-galacto-2-nonulopyranosyl chloride)onate (2) severally with thiophenol in the presence of N,N-di-isopropylethylamine, O-ethyl S-potassium dithiocarbonate, and O-ethyl S-potassium thiocarbonate gave the corresponding 2-thio-α-glycosides 7, 10, and 11, of which 10 was converted into the ethyl 2-thio-α-glycoside 9 on heating with N,N-dimethylformamide-sodium iodide. The phenyl 2-thioglycosides 3 and 7 were converted into the corresponding sulfones. © 1989.I documenti in SFERA sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
