Novel pyranose stereoisomers and method for producing unnatural sugars via palladium catalyzed glycosylation

摘要

The present invention can be a method to prepare a glycosylated natural product or pharmaceutical from either a BocO-pyranone or a BocO-enone. The identical methods of production utilize catalytic palladium and catalytic amounts of phosphine ligand to place the desired group stereospecifically at the C-1 position. The natural product can be the compound digitoxin. Post-glycosylation reactions can add H, OH, F, Cl, Br, I, NH₂, NHAc, CN, or N₃ on C-2, C-3, or C-4 and C-6 can be any alkyl, aryl, heteroalkyl, hydroxyalkyl groups with any amino, halo or hydroxyl substitution. A further aspect of the present invention can be a method to prepare either BocO-pyranone or BocO-enone. Another aspect of the present invention can be the 32 possible pyranose stereoisomers at C-1, C-2, C-3, C-4, or C-6 with substitutes chosen from H, OH, F, Cl, Br, I, NH₂, NHAc, CN, or N₃ on C-2, C-3, or C-4 and C-6 can be any alkyl, aryl, heteroalkyl, hydroxyalkyl groups with any amino, halo or hydroxyl substitution attached to an unnatural sugar attached to a natural product. Further the natural product can be digitoxigenin.