Dichloromethane → 2,3,4,6-Tetra-O-benzyl-1-O-(1-amino-hex-6-yl)-mannopyranose

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Reaction Conditions

Reaction Steps

A mixture that consists of 54.1 g (100 mmol) of 2,3,4,6-tetra-O-benzyl-mannopyranose, 1.39 g (5 mmol) of tetrabutylammonium chloride and 35.84 g (110 mmol) of cesium carbonate in 500 ml of diethoxymethane is cooled to 0° C. At 0° C., 60.3 g (150 mmol) of 6-bromohexylamine-N-(9-fluorenylmethoxy-carbonyl) is added in drops over 30 minutes while being stirred vigorously. It is stirred for one hour at 0° C. 300 ml of dichloromethane is added, the organic phase is separated, and the aqueous phase is extracted twice with 200 ml of dichloromethane. The solvent of the combined organic phases is distilled off in a vacuum. The residue is taken up in 250 ml of ethanol, and 100 g (1.17 mol) of piperidine is added. It is stirred for five hours at 40° C. The solution is evaporated to the dry state, and the residue is chromatographed on silica gel (mobile solvent: dichloromethane/ethanol/triethylamine=20:2:0.1).

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