A Facile Synthesis of (2R3S)-1-Amino-3-tert-butoxycarbonylamino-2-hydroxy-4-phenylbutane;A Useful Component Block of HIV Protease Inhibitor

Abstract (S)-3-tert-Butoxycarbonylamino-1-nitro-2-oxo-4-phenylbutan 4 was converted to (2R, 3S)-1-amino-3-tert-butoxycarbonylamino-2-hydroxy-4-phenylbutane 5a by a catalytic hydrogenation, or NaBH4-TiCl4 reduction followed by hydrogenation in favorable diastereoselectivity, a component of the HIV protease inhibitor VX-478. Notes The HPLC chromatogram showed two signals with tr = 9.9 and 10.6 min assignable to the (2R,3S) and (2S,3S)-diastereomer, respectively. The HPLC chromatogram showed two signals with tr = 13.9 and 15.1 min assignable to the (2S,3S)- and (2R,3S)-diastereomer, respectively.