C-Nucleosides. 21. Synthesis of Isoxazole C-Nucleoside from Furanone Glycoside via Enaminone Glycoside
摘要:
Synthesis of the versatile and stable C-nucleoside precursor enaminone glycosides (3a,b) was achieved by reaction of furanone glycoside (1) with 2- and 4-aminophenols. Treatment of enaminone (3b) with hydroxylamine hydrochloride yielded 5-hydroxy-4,5-dihydroisoxazole(5), which on dehydration with toluene-p-sulfonic acid in benzene gave 5-(2,3,5-tri-O-benzoyl-beta-D-ribofuranosyl)isoxazole (6). Deblocking of compound (6) with sodium carbonate gave 5-(beta-D-ribofuranosyl)isoxazole (7).
C-Nucleosides. 21. Synthesis of Isoxazole C-Nucleoside from Furanone Glycoside via Enaminone Glycoside
摘要:
Synthesis of the versatile and stable C-nucleoside precursor enaminone glycosides (3a,b) was achieved by reaction of furanone glycoside (1) with 2- and 4-aminophenols. Treatment of enaminone (3b) with hydroxylamine hydrochloride yielded 5-hydroxy-4,5-dihydroisoxazole(5), which on dehydration with toluene-p-sulfonic acid in benzene gave 5-(2,3,5-tri-O-benzoyl-beta-D-ribofuranosyl)isoxazole (6). Deblocking of compound (6) with sodium carbonate gave 5-(beta-D-ribofuranosyl)isoxazole (7).