| abstract |
The invention provides compounds of the formulae:n n n in which R is hydrogen or CX 3 . each X, which is the same as or different from the other, is a chlorine or bromine atom, R' is lower alkyl or lower alkoxy, R 2 is hydrogen, lower alkoxycarbonyl or lower alkanoyl, and R 3 is hydrogen or lower alkoxycarbonyl. n The compounds of Formula III are made by intramolecular carbenoid cyclization of compounds of Formula II; the compounds of Formula II are made from compounds of Formula I, e.g. by treatment with azide followed by a base; the compounds of Formula I are prepared by reacting an alcohol of formula:n with a hydrazone. n Those compounds of Formula I in which R is CX 3 can be converted to a compound of the formula:n in which the carboxy and dihalovinyl groups are cis with respect to each other, which are insecticidal, by treatment with certain metals in selected solvents. |