Synthesis of 2-Azido-6-amino and 2-Fluoro-6-amino Analogues of 1-Deoxynojirimycin

1- Aminoglucitol (3) was transformed into iminosugars 5-8, piperidine analogues of manno- and 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 from 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-l,6-dideoxymannojirimycin (5) or 2-azido- and 2-fluoro-6-amino-l,6-dideoxynojirimycin 7 and 8. © 1995, American Chemical Society. All rights reserved.