Citric Acid → (2S,3S)-1,2-Epoxy-3-(Cbz-amino)-4-phenylbutane

Participants

Reaction Conditions

Reaction Steps

25.5 g of the crude N-benzyloxycarbonyl-3(S)-amino-2(R)-p-toluenesulfonyl-4-phenyl-1-butanol obtained in the above Example 1 was dissolved in 750 ml of methanol. Then 13.9 g of potassium carbonate was added thereto at 10° C. and the resulting mixture was stirred for 3 hours at 10° to 20° C. The pH value of the reaction mixture was adjusted to 7 to 7.5 by adding a 5% aqueous solution of citric acid. After distilling off the solvent under reduced pressure, 150 ml of water was added to the concentrate. Then it was extracted with 150 ml portions of ethyl acetate twice and the extract was washed with 50 ml of a saturated aqueous solution of sodium chloride and dried over anhydrous sodium sulfate. After filtering off the sodium sulfate and distilling off the solvent under reduced pressure, 14.4 g of crude N-benzyloxycarbonyl-3(S)-amino-1,2(S)-epoxy-4-phenylbutane was obtained.

Provenance & Evidence