(E)-(R)-4-tert-butoxycarbonylamino-5-(3'-chloro-biphenyl-4-yl)-2-methyl-pent-2-enoic acid ethyl ester → (S)-4-tert-butoxycarbonylamino-5-(3'-chloro-biphenyl-4-yl)-2-methyl-pentanoic acid ethyl ester

Participants

Reaction Steps

Next, to a solution of (E)-(R)-4-tert-butoxycarbonylamino-5-(3′-chloro-biphenyl-4-yl)-2-methyl-pent-2-enoic acid ethyl ester (2.5 g, 5.63 mmol) in ethanol (20 mL) is added Pt/C (250 mg) and the mixture is stirred overnight under an atmosphere of hydrogen (H2 balloon). The catalyst is filtered through a Celite pad and, the filtrate is concentrated to give (S)-4-tert-butoxycarbonylamino-5-(3′-chloro-biphenyl-4-yl)-2-methyl-pentanoic acid ethyl ester.

Provenance & Evidence