(+/-)-10,12-cis-10,11-Dihydro-12-hydroxy-6,6,10,11,11-pentamethyl-4-propyl- 2H,6H,12H-benzo[1,2-b:3,4-b':5,6-b'']tripyran-2-one AIDS-058248 AIDS058248 Calanolide analog