Synthesis of 2-deoxy-2-[82Br]bromo-D-mannose and related compounds and their biodistributions in mice

The synthesis of 2-deoxy-2-[82Br]bromo-3,4,6-tri-O-acetyl-alpha-D-mannopyranosyl chloride (compound 3b) and 2-deoxy-2-[82Br]bromo-D-mannose (compound 4b), and their biodistributions in mice are described. The reaction of 3,4,6-tri-O-acetyl-D-glucal (compound 2) with unlabeled and labeled bromine chloride (compounds 1a and 1b) generated in situ from the oxidation of bromide with N-chloro-succinimide gave unlabeled and labeled 2-deoxy-2-bromo-3,4,6-tri-O-acetyl-alpha-D-mannopyranosyl chloride (compounds 3a and 3b) with a radiochemical yield of 58% (chemical yield, 63%). The hydrolysis of compounds 3a and 3b with 2N HCl gave 2-deoxy-2-bromo-D-mannose (compounds 4a and 4b) with a radiochemical yield of 72%. The biodistribution of compounds 3b and 4b after injection in mice indicated that 2% of the total injected radioactivity rapidly accumulated in the brain, while 6% of the total injected radioactivity accumulated in the heart; however, the radioactivity started to decline in these two organs after 15 min.