Benzyl chloroformate → (2R,4R)-1-((benzyloxy)carbonyl)-4-hydroxypyrrolidine-2-carboxylic acid

Participants

Reaction Steps

A suspension of cis4-hydroxy-D-proline (10.0 g) in THF-water (1:1, 100 mL) was added 1N NaOH solution (50 mL) at 5° C. To the mixture was added a solution of benzyloxycarbonyl chloride (12.5 mL) in THF (10 mL) keeping pH to 8.5-10 by the addition of 2N NaOH solution at 5-10° C. After stirring at the same temperature for 1 h, the reaction mixture was washed with EtOAc (50 mL), adjusted to pH 2 by the addition of 4N HCl, and extracted with EtOAc. The organic layer was washed with water and brine, dried (MgSO4), and evaporated in vacuo to give cis4-hydroxy-N-benzyloxycarbonyl-D-proline (18.74 g).

Provenance & Evidence