Patent ID: 7723319

Claim:
A phosphonate compound represented by the following formula (2): in which represents single bond or double bond, R 1 , R 2 , R 3 , R 7 , and R 8 independently of one another represent hydrogen, halogen, hydroxyl, amino, C 1 -C 7 -alkyl, C 2 -C 6 -alkenyl, C 1 -C 5 -alkylamino, C 1 -C 5 -aminoalkyl, or C 1 -C 5 -alkoxy, R 4 and R 5 independently of one another represent hydrogen, or represent C 1 -C 4 -alkyl optionally substituted by one or more substituents selected from the group consisting of halogen, C 1 -C 4 -alkoxy, phenoxy, C 7 -C 10 -phenylalkoxy and C 2 -C 5 -acyloxy, wherein C 2 -C 5 -acyloxy is RC(O)O— and R is C 2 -C 5 -alkyl, or represent C 1 -C 7 -acyl, wherein C 1 -C 7 -acyl is RC(O)— and R is C 1 -C 7 -alkyl, C 6 -C 12 -aryl or optionally substituted carbamoyl, or represent —(CH 2 )m-OC(═O)—R 6 wherein m denotes an integer of 1 to 12 and R 6 represents C 1 -C 12 -alkyl, C 2 -C 7 -alkenyl, C 1 -C 5 -alkoxy, C 1 -C 7 -alkylamino, di(C 1 -C 7 -alkyl)amino, C 3 -C 6 -cycloalkyl, or 3 to 6-membered heterocycle having 1 or 2 hetero atoms selected from a group consisting of nitrogen and oxygen, Y represents —O—, —S—, —CH(Z)—, ═C(Z)—, —N(Z)—, ═N—, —SiH(Z)—, or ═Si(Z)—, wherein Z represents hydrogen, hydroxyl or halogen, or represents C 1 -C 7 -alkyl, C 1 -C 5 -alkoxy, allyl, hydroxy-C 1 -C 7 -alkyl, C 1 -C 7 -aminoalkyl or phenyl, and L represents a leaving group.