Synthesis and NMR spectroscopic analysis of 3-nitro-pyranoside, 3-nitro-septanoside and 4-nitro-septanoside derivatives by condensation of the anion of nitromethane with glycoside dialdehydes

The utility of the nitroaldol reaction for accessing 3-nitro-pyranoside, 3-nitro-septanoside or 4-nitro-septanoside derivatives, by reaction of the anion of nitromethane with glycoside dialdehydes is demonstrated. Initially, the feasibility of using unprotected glucoside dialdehydes was probed for the synthesis of the septanoside products, but this afforded pyranoside rather than septanoside targets. Subsequent studies utilised protected glycoside dialdehydes within the methodology, which allowed entry into a range of 3-nitro or 4-nitro-septanosides in good yield. NMR spectroscopic analysis allowed determination of the stereochemistry of each of the products thus afforded.

The utility of the nitroaldol reaction for accessing 3-nitro-pyranoside, 3-nitro-septansoide or 4-nitro-septanoside derivatives, by reaction of the anion of nitromethane with glycoside dialdehydes, is described.Figure optionsDownload as PowerPoint slide

Benzyl 3-deoxy-3-nitro-β-d-glucopyranosideC13H17NO7Ee = 100%[α]D20=-29.1 (c 1.01, MeOH)Source of chirality: methyl α-d-glucopyranoside

Methyl 5,7-O-benzylidene-3-deoxy-3-nitro-α-d-glycero-d-altro-septanosideC15H19NO8Ee = 100%[α]D20=+23.7 (c 1.75, MeOH)Source of chirality: methyl α-d-glucopyranoside

Methyl 2-O-benzyl-4-deoxy-4-nitro-7-benzyloxymethyl-α-d-glycero-l-manno-septanosideC22H27NO8Ee = 100%[α]D20=+96.9 (c 1.0, CHCl3)Source of chirality: methyl α-d-glucopyranoside

Methyl 2-O-benzyl-4-deoxy-4-nitro-7-benzyloxymethyl-α-d-glycero-d-talo-septanosideC22H27NO8Ee = 100%[α]D20=+49.4 (c 1.06, CHCl3)Source of chirality: methyl α-d-mannopyranoside