(3S,4aS,8aS,2'R,3'S,3aS,4S,6aR)-N-tert-Butyl-2-[2'-hydroxy-4'-phenyl-3'-[[[(4-hexahydro-2H-cyclopenta[b]furanyl)oxy]carbonyl]amino]butyl]decahydroisoquinoline-3-carboxamide AIDS-028266 AIDS028266 IsoquinCON c-Pen-Thf Urethane analog