The invention relates to novel pesticidally active compounds of the general formula I as well as possible isomers and mixtures of isomers thereof, wherein n is a number zero or one; and R1 is C1-C12alkyl that is unsubstituted or may be substituted by C1-C4alkoxy, C1-C4alkylthio, C1-C4alkylsulfonyl, C3-C8cycloalkyl, cyano, C1C6alkoxycarbonyl, C3-C6alkenyloxycarbonyl or by C3-C6alkynyloxycarbonyl; C3-C8cycloalkyl; C2-C12alkenyl; C2-C12alkynyl; C1-C12haloalkyl: or a group NR11R12 wherein R11 and R12 are each independently of the other hydrogen or C1-C8alkyl, or together are tetra- or penta-methylene; R2 and R3 are each independently of the other hydrogen; C1-C8alkyl; C1-C8alkyl substituted by hydroxy, C1-C4alkoxy, mercapto or by C1-C4alkylthio; C3-C8alkenyl; C3-C8alkynyl; C3-C8cycloalkyl; C3-C8cycloalkyl-C1-C4alkyl; or the two groups R2 and R3 together with the carbon atom to which they are bonded form a three- to eight-membered ring; R4, R5, R6 and R7 are identical or different and are each independently of the others hydrogen or C1-C4alkyl; R8 is C1-C6alkyl, C3-C6alkenyl or C3-C6alkynyl; A is C1-C6alkylene; and B is optionally mono- or poly-nuclear, unsubstituted or substituted aryl; optionally mono- or poly-nuclear, unsubstituted or substituted heteroaryl; C4-C12alkyl; or C3-C8cycloalkyl. The novel compounds have plant-protecting properties and are suitable for protecting plants against infestation by phytopathogenic microorganisms.