(3S,4aS,8aS,2'R,3'S,3R,3aS)-N-tert-Butyl-2-[2'-hydroxy-4'-phenyl-3'-[[[(3-hexahydrofuro[2,3-b]furanyl)oxy]carbonyl]amino]butyl]decahydroisoquinoline-3-carboxamide AIDS-028270 AIDS028270 IsoquinCON Thf-Thf Urethane analog