A description is given of compounds of the formula which in the 4''-position has the (S)-configuration and wherein R.sub.1 is C.sub.1-C.sub.12alkyl, C.sub.3-C.sub.8cycloalkyl; or C.sub.2-C.sub.12alkenyl; R.sub.2 is hydrogen, optionally substituted C.sub.1-C.sub.12alkyl or optionally substituted C.sub.2-C.sub.12alkenyl; R.sub.3 is C.sub.1-C.sub.12alkyl, optionally substituted C.sub.1-C.sub.12alkyl, optionally substituted C.sub.1-C.sub.12alkoxy-C.sub.1-C.sub.12alkyl, optionally substituted C.sub.3-C.sub.12cycloalkyl, optionally substituted C.sub.2-C.sub.12alkenyl; optionally substituted C.sub.4-C.sub.12cycloalkenyl, optionally substituted C.sub.2-C.sub.12alkynyl; or R.sub.2 and R.sub.3 together are a three- to seven-membered alkylene or four- to seven-membered alkenylene bridge in each of which a CH.sub.2 group may have been replaced by O, S or NR.sub.4; X is O or S; R.sub.4 is C.sub.1-C.sub.8alkyl, C.sub.3-C.sub.8cycloalkyl, C.sub.2-C.sub.8alkenyl, C.sub.2-C.sub.8alkynyl, benzyl or C(.dbd.O)--R.sub.5; R.sub.5 is for example H, OH, SH, C.sub.1-C.sub.12alkyl, C.sub.2-C.sub.8alkenyl, C.sub.2-C.sub.8alkynylyl or C.sub.1-C.sub.12haloalkyl; and, where appropriate, E/Z isomers, mixtures of E/Z isomers and/or tautomers thereof, in each case in free form or in salt form; to a process for the preparation of, and to the use of, such compounds and isomers and tautomers thereof; to starting compounds for the preparation of compounds of formula (I); to pesticidal compositions in which the active ingredient has been selected from the compounds of formula (I) and tautomers thereof; and to a method of controlling pests using such compositions. ##STR00001##