Sugar aziridines

The conversion of azidoformates to fused-ring aziridines via the thermal generation of a nitrene has previously been reported. More recently, the photolytic conversion of a sugar-derived azidoformate has been used to prepare fused-ring aziridines <06JOC8059>. Photolysis of azidoformate 66 at 254 nm provides aziridine 67 in excellent yield. The resulting bicyclic aziridine was reduced to provide oxazolidinone 68 in 95% yield. Oxazolidinone 68 was subsequently converted to L-daunosamine. 

The endo-spiro-OZT could be prepared through a reaction sequence similar to that applied for the exo-epimer, with spiro-aziridine intermediates replacing the key spiro-epoxides (Scheme 18). Cyanohydrin formation from ketones was tried under kinetic or thermodynamic conditions, and only reaction with the d-gluco derived keto sugar offered efficient stereoselectivity, while no selectivity was observed for reaction with the keto sugar obtained from protected D-fructose. The (R) -cyanohydrin was prepared in excellent yield under kinetic conditions (KCN, NaHC03, 0 °C, 10 min) a modified thermodynamic procedure was applied to produce the (S)-epimer in 85% yield (Scheme 18). 

Saccharides Containing Aziridine Rings (Epimino Sugars).352... 

Sugar azides are also important starting-materials for the synthesis of epimino sugars an azido group adjacent to a p-tolylsulfonyloxy group, as in 6 or 8, may be simultaneously reduced and cyclized with Raney nickel to form an aziridine ring, as in 7, especially if the two groups are in the frans-diaxial position.19 22... 

Glycoslduloses Cyanomesyl derlv. Sptro-aziridine Branched amino sugar... 

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