D-glucamine (Compound 34: 9.0 g, 49.7 mmol) was mixed with 200 ml of a 10% aqueous solution of sodium carbonate, and this was followed by stirring under ice cooling. 9-Fluorenylmethylsuccinimidyl carbonate (16.7 g, 49.7 mmol) was dissolved in 200 ml of DME (1,2-dimethoxyethane) and added to the reaction system, and this was followed by stirring under ice cooling for 30 minutes. The precipitating crystal was collected by filtration and washed with H2O×3 and MeOH×3. The crystal was dried under reduced pressure to yield the desired compound (2,3,4,5,6-pentahydroxy-hexyl)-carbamic acid 9H-fluoren-9-ylmethyl ester (Compound 35: 20 g) quantitatively.
