Compounds useful as antiviral agents are defined by the following formula: ##STR1## wherein R.sup.1 is hydrogen, --C(Y)OR.sup.7 or --C(O)NHR.sup.7 wherein R.sup.7 is alkyl of one to twelve carbon atoms, alkenyl of two to twelve carbon atoms, cyclopentyl, cyclohexyl, phenyl or benzyl; R.sup.2 is --C(Y)OR.sup.7 or --C(O)NHR.sup.7 wherein R.sup.7 is as defined above; Y is oxygen or sulfur; R.sup.3 is hydrogen, halo, thio, lower alkylthio of one to six carbon atoms, azido, NR.sup.9 R.sup.10 wherein R.sup.9 and R.sup.10 are independently hydrogen or lower alkyl of one to six carbon atoms or --NHC(O)R.sup.8 wherein R.sup.8 is hydrogen, alkyl of one to nineteen carbon atoms or 1-adamantyl; and (a) R.sup.6 is hydrogen, halo, lower alkoxy of one to six carbon atoms, azido, thio, lower alkylthio of one to six carbon atoms, --NR.sup.9 R.sup.10 wherein R.sup.9 and R.sup.10 are as defined above or --NHC(O)R.sup.8 wherein R.sup.8 is as defined above and R.sup.4 together with R.sup.5 is a bond; or (b) R.sup.5 together with R.sup.6 is a keto group and R.sup.4 is hydrogen.
有用作抗病毒剂的化合物的定义如下:##STR1## 其中 R.sup.1 是氢,-C(Y)OR.sup.7或-C(O)NHR.sup.7,其中R.sup.7是一到十二个碳原子的烷基,二到十二个碳原子的烯基,环戊基,环己基,苯基或苄基;R.sup.2是-C(Y)OR.sup.7或-C(O)NHR.sup.7,其中R.sup.7如上所述;Y是氧或
硫;R.sup.3是氢,卤素,
硫,一到六个碳原子的低烷基
硫,偶氮基,NR.sup.9R.sup.10,其中R.sup.9和R.sup.10独立地是氢或一到六个碳原子的低烷基,或-NHC(O)R.sup.8,其中R.sup.8是氢,一到十九个碳原子的烷基或1-
金刚烷基;以及(a)R.sup.6是氢,卤素,一到六个碳原子的低烷氧基,偶氮基,
硫,一到六个碳原子的低烷基
硫,-NR.sup.9R.sup.10,其中R.sup.9和R.sup.10如上所述或-NHC(O)R.sup.8,其中R.sup.8如上所述,R.sup.4与R.sup.5一起是键;或(b)R.sup.5与R.sup.6一起是酮基,R.sup.4是氢。