Compounds having the formula I and salts and solvates, wherein, when a double bond is present between C2 and C3, R2 is selected from the group consisting of: (ia) halo, A C5-10 aryl group optionally substituted by one or more substituents selected from the group consisting of nitro, cyano, ether, C1-7 alkyl, C3-7 heterocyclyl and bis-oxy-C1-3 alkylene； ib) C1-5 saturated aliphatic alkyl； (ic) C3-6 saturated cycloalkyl； (id) each of R11, R12 and R13 is independently H, C1-3 saturated alkyl, C2-3 alkenyl, C2 Selected from -3 alkynyl and cyclopropyl, the total number of carbon atoms in the R2 group is 5 or less； (ie) one of R15a and R15b is H and the other is phenyl (phenyl is optional in halo, methyl, methoxy ), (If) R14 is selected from H, C1-3 saturated alkyl, C2-3 alkenyl, C2-3 alkynyl, cyclopropyl, phenyl (phenyl is a group selected from halo, methyl, methoxy) Optionally substituted), selected from pyridyl and thiophenyl； when a single bond is present between C2 and C3, R2 is and R16a and R16b are independently H, F, C1 -4 saturated alkyl, selected from C2-3 alkenyl, the alkyl and alkenyl groups are optionally substituted with a group selected from C1-4 alkylamide and C1-4 alkyl ester, or one of R16a and R16b is H In some cases, the other is selected from nitriles and C1-4 alkyl esters； when a double bond is present between C2 ′ and C3 ′, R12 is a group consisting of (Ia) one or more substituents selected from the group consisting of halo, nitro, cyano, ether, carboxy, ester, C1-7 alkyl, C3-7 heterocyclyl and bis-oxy-C1-3 alkylene (Ib) a C1-5 saturated aliphatic alkyl； (ic) a C3-6 saturated cycloalkyl； (id) each of R21, R22 and R23 is independently H , C1-3 saturated alkyl, C2-3 alkenyl, C2-3 alkynyl and cyclopropyl, wherein the total number of carbon atoms in the R12 group is 5 or less； (ie) one of R25a and R25b is H； Is selected from phenyl (phenyl is optionally substituted with halo, methyl, methoxy), pyridyl and thiophenyl； (if) R24 is H, C1-3 saturated alkyl,
