1-[4-(Pyridin-2-yl)-phenyl]-4(S)-hydroxy-2-N-(N-methoxycarbonyl-(L)-tert-leucyl)amino]-5(S)-N-(N-methoxycarbonyl-(L)-valyl)amino-6-phenyl-2-azahexane AIDS-057758 AIDS057758 Heterocyclic Azahexane deriv.