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

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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