Functionalization of Terminal Positions of Sucrose—Part I: Synthesis of 2,3,3′,4,4′-Penta-O- Benzylsucrose and Differentiation of the Terminal Positions (1,6,6′)

Experimental Methods ........................................................................................... 389 General Methods ............................................................................................... 3891′,6,6′-Tri-O-Tritylsucrose (2) .....................................................................390 2,3,3′,4,4′-Penta-O-Benzyl-1′,6,6′-Tri-O-Tritylsucrose (3) ......................... 391 2,3,3′,4,4′-Penta-O-Benzylsucrose (4) ......................................................... 391 2,3,3′,4,4′-Penta-O-Benzyl-6,6′-Di-O-p-Nitrobenzoylsucrose (5) .............. 392 2,3,3′,4,4′-Penta-O-Benzyl-1′-O-Benzyloxymethyl-6,6′-Di-O-pNitrobenzoylsucrose (6) ............................................................................... 392 2,3,3′,4,4′-Penta-O-Benzyl-1′-O-Benzyloxymethylsucrose (7) .................. 392 2,3,3′,4,4′-Penta-O-Benzyl-1′-O-Benzyloxymethyl-6′-O-TertButyldiphenylsilylsucrose (8) ....................................................................... 393Sucrose is by far the cheapest and most common disaccharide, exploited mainly by the food industry. Its derivatives have also found application in other areas: surfactants, biodegradable polymers, biochemistry, and supramolecular chemistry.1 Thus, sucrose has become a useful synthon for advanced materials in many research laboratories. There is, however, only a limited number of communications describing chemical transformations of sucrose in detail. This results mostly from insuf¥cient knowledge of important factors (steric, electronic, etc.) that control selectivity and reactivity of individual functional groups of this disaccharide. Several examples of selective transformations of hydroxyl groups of sucrose were described in a recent review.1 Most of the methodologies involve simple etheri¥cation, esteri¥cation, and oxidation reactions. Clearly, there is a need for synthetic procedures, which would provide sucrose derivatives with high added value. The following chapters provide such procedures, leading to sucrose derivatives modi¥ed at the terminal positions.