PROCESS FOR PREPARING INSECTICIDE INTERMEDIATES

摘要

The invention provides compounds of the formulae: in which R is hydrogen or CX3, each X, which is the same as or different from the other, is a chlorine or bromine atom, R<1> is lower alkyl or lower alkoxy, R<2> is hydrogen, lower alkoxycarbonyl or lower alkanoyl, and R<3> is hydrogen or lower alkoxycarbonyl. 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: with a hydrazone. Those compounds of Formula I in which R is CX3 can be converted to a compound of the formula: 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.