Carbon Dioxide → 1-Methylethyl 4-[(1r)-1-({5-[4-(methylsulfonyl)phenyl]-2-pyrazinyl}oxy)ethyl]-1-piperidinecarboxylate

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Reaction Steps

The racemic 1-methylethyl 4-[1-({5-[4-(methylsulfonyl)phenyl]-2-pyrazinyl}oxy)ethyl]-1-piperidinecarboxylate (prepared as in Example 162) was subjected to Chiral HPLC [column: AS-H, column mobile phase: 85% CO2: 15% MeOH (2 mL/min), pressure 140 bar, temperature 40° C., 215 nm] analysis and then separated to give two (R and S) enantiomers, which were further purified by chromatography on an ISCO silica gel column using 0 to 50% EtOAc/hexanes. The title compound was isolated as a white foam with Tr of 17.00 min (second eluting peak). The (R) absolute stereochemistry was assigned by Ab initio VCD analysis.

Provenance & Evidence