Synthesis of L-glycero-D-manno-heptopyranose-containing oligosaccharide structures found in lipopolysaccharides from Haemophilus influenzae

Syntheses are described of the tetrasaccharide 2-(4-trifluoroacetamidophenyl)ethyl O-(β-d-galactopyranosyl)-(1 → 2)-O-(l-glycero-α-d-manno-heptopyranosyl)-(1 → 2)-O-(l-glycero-α-d-manno-heptopyranosyl)-(1 → 3)-l-glycero-α-d-manno-heptopyranoside (20) and the three trisaccharides 2-(4-trifluoroacetamidophenyl)ethyl O-(l-glycero-α-d-manno-heptopyranosyl)-(1 → 2)-O-(l-glycero-α-d-manno-heptopyranosyl)-(1 → 3)-l-glycero-α-d-manno-heptopyranoside (17), 2-(4-trifluoroacetamidophenyl)ethyl O-(β-d-glucopyranosyl)-(1 → 4)-O-(β-d-glucopyranosyl)-(1 → 4)-l-glycero-α-d-manno-heptopyranoside (5), and 2-(4-trifluoroacetamidophenyl)ethyl O-(β-d-galactopyranosyl)-(1 → 4)-O-(β-d-glucopyranosyl)-(1 → 4)-l-glycero-α-d-manno-heptopyranoside (8), corresponding to structures found in the lipooligosaccharides of Haemophilus influenzae. © 1997 Elsevier Science Ltd.