2H-2,4a-Ethenonaphtho[2,1-c][1,2]dioxin-7-carboxylic acid, 1,5,6,6a,7,8,9,10,10a,10b-decahydro-7,10a-dimethyl-12-(1-methylethyl)-, methyl ester AIDS-138678 AIDS138678 NSC645994