SYNTHESIS OF 2-AZIDO-6-AMINO AND 2-FLUORO-6-AMINO ANALOGS OF 1-DEOXYNOJIRIMYCIN

1-Aminoglucitol (3) was transformed into iminosugars 5-8, piperidine analogues of manno- ana glucopyranose, by using a reversed-chain strategy in which the 1-amino group of 3 is retained as the 6-substituent of the iminosugars and the ring nitrogen is derived fi om an azido group introduced at C-2 of the N-Boc-3,4:5,6-O-diisopropylidene protected derivative 9. Successive deprotection of the 5,6-diol moiety, reduction of the azido group, and displacement of 6-OH with a bromo substituent result in generation of the iminosugar synthon 4. This can be deprotected directly or following inversion at the C-2 position to afford 6-amino-1,6-dideoxymannojirimycin (5) or 2-azido- and, 2-fluoro-6-amino-1,6-dideoxynojirimycin 7 and 8.