Syntheses of difluorinated carbasugar phosphates from trifluoroethanol

Difluorinated cyclohexene diols (prepd. from trifluoroethanol) can be elaborated to racemic analogs of phosphorylated sugars via regioselective protection and phosphorylation of the exposed C-1 hydroxyl group. Cis-diol protection was achieved using stannylene methodol., though the regioselectivity depended on the orientation of the Me group at C-5. UpJohn dihydroxylation is effective with the phosphotriester in place and global deprotection to the tetrol monophosphates I (R1 = OH, R2 = H; R1 = H, R2 = OH) is efficient.