Sodium borohydride → trans-1-(p-nitrobenzyloxycarbonyl)-4-hydroxy-L-proline p-methoxybenzyl ester

Participants

Reaction Steps

650 mg of 1-(p-nitrobenzyloxycarbonyl)-4-oxo-L-proline p-methoxybenzyl ester was dissolved in 45 ml of ethanol, and 86 mg of sodium borohydride was added thereto in two divided portions at room temperature. After 30 minutes, the reaction mixture was concentrated under reduced pressure at 30° C. or below, and the concentrate was diluted with ethyl acetate, washed with water, dried over sodium sulfate and distilled off to remove the solvent. The residue was purified by silica gel column chromatography to obtain cis-1-(p-nitrobenzyloxycarbonyl)-4-hydroxy-L-proline p-methoxybenzyl ester (450 mg) and trans-1-(p-nitrobenzyloxycarbonyl)-4-hydroxy-L-proline p-methoxybenzyl ester (190 mg).

Provenance & Evidence