An alternative synthesis of 4-deoxy-4-fluoro-D-glucose and its transport in the human erythrocyte.

Treatment of methyl 4-O-mesy-alpha-D-galactopyranoside with benzyl bromide in N,N-dimethylformamide in the presence of silver oxide yielded methyl 2,3,6-tri-O-benzyl-4-O-mesyl-alpha-D-galactopyranoside which with tert-butylammonium fluoride at reflux underwent nucleophilic displacement to give methyl 2,3,6-tri-O-benzyl-4-deoxy-4-fluoro-alpha-D-glucopyranoside. This compound on hydrogenolysis provided crystalline methyl 4-deoxy-4-fluoro-alpha-D-glucopyranoside (9). The structure of 9 was established by its conversion to the 2,3,6-tri-O-acetyl derivative and by n.m.r. and m.s. analysis. Acid hydrolysis of 9 gave 4-deoxy-4-fluoro-D-glucose (1). A modification of an established synthesis of 4-deoxy-D-xylo-hexose (2) from methyl 2,3,6-tri-O-benzoyl-alpha-D-galactopyranoside is described. A systematic comparison was made of the transport parameters (Kx and Vmax) of D-glucose, 2, and 1 in human erythrocytes. The Kx values observed for the above sugars are: 4.0mM, 4.5mM, and 4.6mM, respectively. These results indicate that O-4 in beta-D-glucopyranose is not involved in hydrogen bonding to the carrier protein associated with the transport of D-glucose in the erythrocyte.