4,5-Benzospiro(2,4)-heptane (and hepta-4,6-diene)-1-carboxylic acid esters and compositions containing same

#The present invention relates to 2,2-dimethyl-4,5-benzospiro(2,4)heptane-1-carboxylic acid esters and 2,2-dimethyl-4,5-benzospiro(2,4)hepta-4,6-diene-1-carboxylic acid esters, to processes for producing them and to their use in combatting pests.

#The esters according to the invention have the formula ##STR2## wherein

#R.sub.1 and R.sub.2 are each hydrogen or together are a carbon-carbon bond.

#The invention is further illustrated by the following Examples.

#To a solution of 4.4 g (0.0205 mole) of 2,2-dimethyl-4,5-benzospiro(2,4)hepta-4,6-diene-1-carboxylic acid in 50 ml of hexamethylphosphoric acid triamide is added 3.1 g (0.022 mole) of potassium carbonate. An addition is then made dropwise of 4.15 g (0.02 mole) of 2-benzyl-4-chloromethyl-furan, and the reaction mixture is stirred for 18 hours at room temperature. In further processing, the reaction mixture is poured into water and extracted with ether. The ether phase is subsequently washed twice with water and twice with saturated sodium chloride solution. After drying over sodium sulphate, the solvent is distilled off and the oily residue is purified by column-chromatography (silica gel/ether/hexane = 1 : 4) to obtain the product of the formula ##STR7## as a diastereomeric mixture: n.sub.D.sup.20 = 1.5842.

#The compounds of the following formula are produced in an analogous manner: ##STR8##