Water → HCID 68769784, compound

Participants

Reaction Steps

Example 13a, Step 1 (Isomerization of the cis ester to the corresponding trans ester): To a solution of (1R,2S,5R)-methyl 2-((S)-3-(benzyloxycarbonylamino)-2-oxopyrrolidin-1-yl)-5-(tert-butoxycarbonylamino)-cyclohexanecarboxylate (281 mg, 0.573 mmol, see Example 12a, Step 3) in anhydrous DMF was added cesium carbonate (747 mg, 2.29 mmol), and the mixture was stirred for 16 h at rt. At the end of the stirring the mixture was poured into water, and extracted with EtOAc (3×). The combined extracts were washed with water, dried (Na2SO4), filtered, and concentrated in vacuo. The residue was purified by flash chromatograpy on silica gel with elution by EtOAc to afford pure trans isomer, (1S,2S,5R)-methyl 2-((S)-3-(benzyloxycarbonyl)amino-2-oxopyrrolidin-1-yl)-5-(tert-butoxycarbonyl)amino-cyclohexanecarboxylate (214 mg) as an oil.

Provenance & Evidence