| abstract |
A compound of formula (I) wherein R 1 is (1) unsubstituted, (2) a hydrogen atom, (3) a hydrocarbon group optionally having a substituent (s) selected from the group A of substituents or (4) acyl; R 2 is (1) a hydrogen atom, (2) a hydrocarbon group optionally having a substituent (s) selected from the group of substituents A, (3) hydroxy optionally having a hydrocarbon group optionally having a substituent (s) selected from the group of substituents A, ( 4) an amino optionally having 1 or 2 hydrocarbon groups optionally having a substituent (s) selected from the group of substituents A, (5) a group of formula -SR20 wherein R20 is a hydrocarbon group optionally having a substituent (s) selected from the group of substituents A, (6) a group of formula-S (O) R21, wherein R21 is a hydrocarbon group optionally having a substituent (e) selected from the group of substituents A, (7) a group of formula-S (O) 2R22 wherein R22 is a hydrocarbon group optionally has a substituent (s) selected from the group of substituents A, (8) a heterocyclic group optionally having a substituent (s) selected from the group of substituents A or (9) acyl; R3 is (1) unsubstituted, (2) a hydrogen atom, (3) a hydrocarbon group optionally having a substituent (s) selected from the group of substituents A, (4) hydroxy optionally having a hydrocarbon group optionally having a substituent (s) selected from the group substituents A, (5) amino optionally having 1 or 2 hydrocarbon groups, which optionally have a substituent (s) selected from the group of substituents A, (6) a group of formula -SR20 wherein R20 is a hydrocarbon group optionally having a substituent (s) selected from the group of substituents A, (7) a group of formula -S (O) R21 in which R22 is a hydrocarbon group optionally having a substituent (e) selected from the group of substituents A, (8) a group of formula -S (O) 2R22 in which R22 is a hydrocarbon group optionally having a substituent (s) selected from the group of substituents A or (9) acyl; R 4 and R 5 are the same or different and each (1) is a hydrogen atom, (2) a hydrocarbon group optionally having a substituent (s) selected from the group of substituents A, (3) hydroxy optionally having a hydrocarbon group optionally having a substituent (s) selected from the group of substituents A, (4) amino which optionally has 1 or 2 hydrocarbon groups optionally having a substituent (e) selected from the group of substituents A, (5) a group of formula -SR20 wherein R20 is a hydrocarbon group optionally having a substituent (e) ) selected from the group of substituents A, (6) a group of formula -S (O) R21 in which R21 is a hydrocarbon group optionally having a substituent (e) selected from the group of substituents A, (7) a group of formula -S (O) 2R22 in which R22 is a hydrocarbon group optionally having a substituent (e) selected from the group of substituents A or (8) acyl; R6 is (1) (cyclic group optionally having a substituent (s) selected from the group of substituents A) -carbonyl, (2) alkenylcarbonyl optionally having a substituent (s) selected from the group of substituents A, (3) alkylcarbonyl having a substituent (e) ) selected from the group consisting of (i) cycloalkyl |