Synthesis and reactions of halodeoxy sucrose.: Part 2.: Synthesis and taste properties of 4,1′,6′-trihalodeoxy sucrose analogues

Treatment of 3,4-di-O-acetyl-1,6-di-O-trityl-beta -D-fructofuranosyl 2,3,6-tri-O-acetyl-4-O-triflyl-alpha -D-galactopyranoside (3) with a halide source gave, via S(N)2 displacement, the corresponding C-4 halogenated compounds which were subsequently transformed into the monohalogenated 4-deoxy-4-halogenosucrose derivatives, 10-12. Trihalogenated sucrose derivatives, 4-bromo-1',6'- dichloro 17, 1',6'-dibromo 18, and 1',6'-diiodosucrose 19, were synthesized from 5. Exploiting the distinct reactivity at C-1' and C-6' trifluoromethanesulfonates enabled the introduction of different halogens at these positions. This pathway led to the preparation of the 4-bromo-1',6'-dihalodeoxysucrose derivatives, 24-27. Preliminary taste properties of these mono- and tri-halogenated sucrose analogues were also investigated.