Ethanethiol → (2S)-2-[(1R,2S)-2-benzyloxycarbonyl-1-ethylsulfanyl-propyl]-pyrrolidine-1-carboxylic acid tert-butyl ester

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Reaction Steps

To a stirred suspension of t-BuOK (609 mg, 5.43 mmol) in THF (90 ml) was added EtSH (8.04 ml, 0.11 mol). After stirring for 30 min at room temperature, a solution of (2S)-2-(2-benzyloxycarbonyl-propenyl)-pyrrolidine-1-carboxylic acid tert-butyl ester (3.75 g, 10.8 mmol) in THF (75 ml) was added to the mixture. After 2.5 h, the mixture was quenched with saturated NH4Cl aqueous solution, and then concentrated in vacuo. The residue was diluted with EtOAc (400 ml), and washed with saturated NH4Cl aqueous solution (150 ml), saturated NaHCO3 aqueous solution (150 ml) and H2O (150 ml). The organic layer was dried over anhydrous Na2SO4, and then concentrated in vacuo. The residue was purified by column chromatography on silica gel (hexane/EtOAc=12/1 to 8/1) to give (2S)-2-[(1R,2S)-2-benzyloxycarbonyl-1-ethylsulfanyl-propyl]-pyrrolidine-1-carboxylic acid tert-butyl ester (3.66 g, 83%).

Provenance & Evidence