REGIOSPECIFIC SYNTHESES OF AZIDODEOXY AND DIAZIDODIDEOXY DERIVATIVES OF METHYL ALPHA-D-ARABINOFURANOSIDE

Treatment of methyl 2,3-anhydro-α-d-lyxofuranoside with ammonium azide gave only crystalline methyl 3-azido-3-deoxy-α-d-arabinofuranoside (95%). Under analogous conditions, methyl 2,3-anhydro-5-O-p-tolylsulfonyl-α-d-lyxofuranoside gave only methyl 3,5-diazido-3,5-dideoxy-α-d-arabinofuranoside (84%), isolated as its crystalline 2-p-nitrobenzoate; methyl 2,3-anhydro-α-d-ribofuranoside gave methyl 2-azido-2-deoxy-α-d-arabinofuranoside and methyl 3-azido-3-deoxy-α-d-xylofuranoside (3:2; 85%); methyl 2,3-anhydro-5-O-p-tolylsulfonyl-α-d-ribofuranoside gave only methyl 2,5-diazido-2,5-dideoxy-α-d-arabinofuranoside (84%), isolated as its crystalline 3-p-nitrobenzoate; and methyl 2,3-anhydro-5-O-benzoyl-α-d-ribofuranoside gave predominantly methyl 2-azido-5-O-benzoyl-2-deoxy-α-d-arabino-furanoside, isolated as its crystalline 3-p-nitrobenzoate (85%). These findings are discussed on the basis of steric and electronic effects. © 1979.