Hydrochloric Acid → (2S)-1-((benzyloxy)carbonyl)-4-hydroxypyrrolidine-2-carboxylic acid

Participants

Reaction Steps

26.5 g (0.20 mole) of 4-hydroxy-L-proline and 32.8 ml. (0.23 mole) of benzyl chloroformate are reacted in 200 ml. of water and 100 ml of acetone in the presence of 20 g (0.02 mole) of potassium bicarbonate and 69.2 g (0.50 mole) of potassium carbonate and worked up with 90 ml of concentrated hydrochloric acid as described in Can. J. Biochem. & Physiol. 37, 584 (1959) to obtain N-carbobenzyloxy-4-hydroxy-L-proline. This product is reacted with cyclohexylamine to form the cyclohexylamine salt yield 69 g, m.p. 193°-195°. The salt (34 g) is neutralized with N-hydrochloric acid to obtain 27 g of free acid as a colorless glass [α]D26 -70°, (c, 1% in chloroform).

Provenance & Evidence