Methanol → 1-tert-butyl 2-methyl (2S,4EZ)-4-(methoxyimino)-1,2-pyrrolidinedicarboxylate

Participants

Reaction Steps

A solution was made containing, e.g., (4EZ)-1-(tert-butoxycarbonyl)-4-(methoxyimino)-2-pyrrolidinecarboxylic acid (Intermediate 2, 17.81 mmoles; 4.6 gr) in a 1:1 mixture of methanol and toluene (250 mL). Trimethylsilyl diazomethane (32.5 mL of a 2M solution in hexanes, 59 mmol) was then added dropwise to the sirred solution at room temperature under nitrogen. After completion of the evolution of nitrogen gas, the resulting yellow solution was evaporated in vacuo, and the residue re-dissolved in DCM and washed with NH4Clsat and 10% NaHCO3, and brine, dried over Na2SO4 and evaporated in vacuo, giving the desired compound, 1-tert-butyl 2-methyl (2S,4EZ)-4-(methoxyimino)-1,2-pyrrolidinedicarboxylate, as a yellow oil (4.0 g, 83%).

Provenance & Evidence