(+/-)-PM-92131 AIDS-059291 AIDS059291 Indeno[1,7a-b]oxiren-2(1aH)-one, 3-(3-furanyl)hexahydro-3a,7,7-trimethyl-, (1aS,3S,3aS,7aS)- & (1aR,3R,3aR,7aR)-