Synthesis of pseudo-C-nucleosides.
Whereas the reaction of 1,2-O-isopropylidene-alpha-D-xylo-5-hexulofuranuronamide (1) with the Wittig reagent ethoxycarbonylmethylenetriphenylphosphorane gave 3-(1,2-O-isopropylidene-beta-L-threofuranos-4-yl)maleimide (2, 15%) and ethyl 5-carbamoyl-5,6-dideoxy-1,2-O-isopropylidene-alpha-D-xylo-hept-5-enof uranuronate (3, 76%), a similar reaction of 3-O-benzyl-1,2-O-isopropylidene-alpha-D-ribo-5-hexulofuranuronamide++ + (4) gave only 3-(3-O-benzyl-1,2-O-isopropylidene-alpha-D-erythrofuranos-4-yl)mal eimide (5), 80%), and that of 3-O-benzyl-1,2-O-isopropylidene-alpha-D-xylo-5-hexulofuranuronamide++ + (6) gave only ethyl 3-O-benzyl-5-carbamoyl-5,6-dideoxy-1,2-O-isopropylidene- alpha-D-xylo-hept-5-enofuranuronate (7, 85%). The formation of the maleimide ring depended on the orientation and substitution of HO-3'. Compounds 2 and 5 are analogous of showdomycin.
Rauter
A P
AP
Departamento de Química da Faculdade de Ciências da Universidade de Lisboa, Portugal.
Figueiredo
J A
JA
Ismael
I M
IM
D000903:Antibiotics, Antineoplastic / Q000138:chemical synthesis*; D007202:Indicators and Reagents; D009682:Magnetic Resonance Spectroscopy; D009705:Nucleosides / Q000138:chemical synthesis*; D012787:Showdomycin / Q000031:analogs & derivatives / Q000138:chemical synthesis*
D000903:Antibiotics, Antineoplastic; D007202:Indicators and Reagents; D009705:Nucleosides; C061069:3-(1,2-O-isopropylidene-threofuranos-4-yl)maleimide; C061070:3-(3-O-benzyl-1,2-O-isopropylidene-erythrofuranos-4-yl)maleimide; D012787:Showdomycin