SYNTHESIS AND REACTIONS OF 3,4-DI-O-ACETYL-6-AMINO-6-DEOXY-D-GLUCAL AND 6-ACETAMIDO-3,4-DI-O-ACETYL-6-DEOXY-D-GLUCAL

The reduction of 3,4-di-O-acetyl-6-azido-6-deoxy-D-glucal (3a) with nickel boride gives the aminoglycal 1; whereas reduction with thiolacetic acid leads directly to the amidoglycal 2. The aminoglycal 1 is sensitive to aqueous acid and rearranges to (1R)-(2-furyl)-2-acetamidoethanol (4). This furan gives a Diels-Alder adduct 5 with N-phenylmaleimide in which the nitrogen and oxygen on the side chain have interchanged positions. In contrast, the amidoglycal 2 reacts with ammonium nitrate in trifluoroacetic anhydride and with acidic mercuric sulfate to give (E)-5-acetamido-(3S)-acetoxy-(4R)-formoxy-1-nitro-1-pentene (6) and 6-acetamido-4-O-acetyl-2,3,6-trideoxy-aldehydo-D-erythro-trans-hex-2-enose (7) respectively. The amidoglycal 2 also undergoes an intramolecular palladium (II) catalyzed cyclization reaction leading to a pair of diastereomeric (4R)-acetoxy-7-acetyl-7-aza-2-oxabicyclo[3.2.1]oct-5-enes (8).