The 2,1′- O-isopropylidene derivative ( 1) of 3- O-acetyl-4,6- O-isopropylidene-α- d-glucopyranosyl 6- O-acetyl-3,4-anhydro-β- d- lyxo-hexulofuranoside and 2,3,4-tri- O-acetyl-6- O-trityl-α- d-glucopyranosyl 3,4-anhydro-1,6-di- O-trityl-β- d- lyxo-hexulofuranoside have been synthesised and 1 has been converted into 2,3,4,6-tetra- O-acetyl-α- d-glucopyranosyl 1,6-di- O-acetyl-3,4-anhydro-β- d- lyxo-hexulofuranoside ( 2). The S N2 reactions of 2 with azide and chloride nucleophiles gave the corresponding 2,3,4,6-tetra- O-acetyl-α- d-glucopyranosyl 1,3,6-tri- O-acetyl-4-azido-4-deoxy-β- d-fructofuranoside ( 6) and 2,3,4,6-tetra- O-acetyl-α- d-glucopyranosyl 1,3,6-tri- O-acetyl-4-chloro-4-deoxy-β- d-fructofuranoside ( 8), respectively. The azide 6 was catalytically hydrogenated and the resulting amine was isolated as 2,3,4,6-tetra- O-acetyl-α- d-glucopyranosyl 4-acetamido-1,3,6-tri- O-acetyl-4-deoxy-β- d-fructofuranoside. Treatment of 5 with hydrogen bromide in glacial acetic acid followed by conventional acetylation gave 2,3,4,6-tetra- O-acetyl-α- d-glucopyranosyl 1,3,6-tri- O-acetyl-4-bromo-4-deoxy-β- d-fructofuranoside. Similar S N2 reactions with 2,3,4,6-tetra- O-acetyl-α- d-glucopyranosyl 1,6-di- O-acetyl-3,4-anhydro-β- d- ribo-hexulofuranoside ( 12) resulted in a number of 4′-derivatives of α- d-glucopyranosyl β- d-sorbofuranoside. The regiospecific nucleophilic substitution at position 4′ in 2 and 12 has been explained on the basis of steric and polar factors.