Replacement of the decahydroisoquinoline group contained in Ro 3 1-895
9 by a cis-octahydrothienopyridine moiety has provided a high affinity
hydroxyethylamine isostere for use in HIV-I protease inhibitors. Furt
her gains in potency have been realized by incorporation of a sulfur a
tom into the P-1 benzyl group. Modification by a key P-2 ligand provid
ed LY316340, a potent orally absorbed inhibitor of HIV-1 protease.