Alkene, alkyne or cycloalkylene derivatives

A compound of the formula ##STR29## wherein X has the formula ##STR30## wherein ring A is phenyl, naphthyl, pyridyl, quinolyl or thienyl;

• wherein R.sup.1 is hydrogen, alkanoyl of up to 6 carbon atoms or aroyl of up to 10 carbon atoms;
• wherein R.sup.2, R.sup.3 and R.sup.4, which may be the same of different, each is an electron withdrawing substituent selected from halogeno, nitro, cyano and trifluoromethyl, and alkylthio, alkylsulphinyl and alkylsulphonyl each of up to 6 carbon atoms, or each is hydrogen or alkyl, alkoxy or dialkylamino each of up to 6 carbon atoms, provided that when ring A is phenyl or naphthyl at least one of R.sup.2, R.sup.3 and R.sup.4 is an electron-withdrawing substituent;
• wherein R.sup.5 and R.sup.6, which may be the same or different, each is hydrogen, halogeno or alkyl of up to 6 carbon atoms;
• wherein R.sup.7 is halogenoalkyl of up to 6 carbon atoms;
• and wherein R.sup.8 is carbamoyl, alkyl, cycloalkyl, alkenyl, alkynyl, halogenoalkyl, halogenoalkenyl, halogenoalkynyl or alkanoyl each of up to 6 carbon atoms, or alkylcarbamoyl or dialkylcarbamoyl wherein each alkyl is of up to 6 carbon atoms, or aroyl of up to 10 carbon atoms;
• or wherein R.sup.8 is alkyl or alkenyl each of up to 6 carbon atoms which bears one or more substituents selected from cyano, carbamoyl, amino and hydroxy, alkanoyl, alkoxy, alkylthio, alkenylthio, alkylsulphinyl, alkenylsulphinyl, alkylsulphonyl, alkenylsulphonyl, alkanoylamino, alkoxycarbonylamino and alkylsulphonamido each of up to 6 carbon atoms, alkylamino, dialkylamino and dialkylsulphamoyl wherein each alkyl is of up to 6 carbon atoms, aroyl, aryl, arylthio, arylsulphinyl and arylsulphonyl each of up to 10 carbon atoms and heterocyclylthio, heterocyclylsulphinyl and heterocyclylsulphonyl and wherein the heterocyclyl group in R.sup.8 is a 5- or 6-membered saturated or unsaturated heterocyclic which contains one, two or three hetero atoms selected from oxygen, nitrogen and sulphur, which heterocyclic is a single ring or is fused to one or two benzo-rings or to another heterocyclic ring as defined above, and which heterocyclic is unsubstituted or bears substituents R.sup.2, R.sup.3 and R.sup.4 as defined above, or may also bear one or more hydroxy, mercapto or amino substituents;
• or wherein R.sup.8 has the formula ##STR31## wherein ring B is phenyl or naphthyl or ring B is pyridyl or thiazolyl which is unsubstituted or bears a halogeno or trifluoromethyl substituent, or is unsubstituted 1,3-dithian-2-yl.