Fmc Corporation

Toshiyuki Takashima

Kiyoshi Kondo

Minoru Suda

Daiei Tunemoto

Processes for producing a (1.alpha., 4.alpha., 5.alpha.)-6,6-dimethyl-4-halo-substituted methyl-3-oxabicyclo[3.1.0]hexan-2-one and its novel intermediates from known and inexpensive starting materials are described and exemplified.

3,4-dihydro-4,4-dimethyl-2H-pyran-2-one, an insecticide intermediate

Lactones of the formula ##STR1## wherein R is hydrogen or a CX.sub.3 group, and each X is a chlorine or bromine atom, are converted to the known cis-3-(2,2-dihalovinyl)-2,2-dimethylcyclopropanecarboxylic acids or lower alkyl esters, from which pyrethroid insecticides are obtained.

Alkyl 6,6-dimethyl-2-oxo-3-oxabicyclo[3.1.0]hexane-1-carboxylates

Processes for producing a (1.alpha., 4.alpha., 5.alpha.)-6,6-dimethyl-4-halo-substituted-methyl-3-oxabicyclo[3.1.0]hexan- 2-one and its novel intermediates from known and inexpensive starting materials are described and exemplified.

Lower alkyl 5-chloro-3,3-dimethyl-5-phenylthiopentanoates useful as

Novel intermediates for production of insecticidal cis-3-(2,2-disubstituted-ethenyl)-2,2-dimethylcyclopropanecarboxylates, processes for preparing the intermediates, and processes for preparing the final product insecticides via a novel bicyclic lactone intermediate are described and exemplified.

Process for producing

Processes for producing a (1.alpha., 4.alpha., 5.alpha.)-6,6-dimethyl-4-halo-substituted-methyl-3-oxabicyclo[3.1.0]hexan- 2-one and its novel intermediates from known and inexpensive starting materials are described and exemplified. The halomethyl bicyclic lactone is a useful intermediate for the preparation of insecticidal cis-3-(2,2-dihaloethenyl)-2,2-dimethylcyclopropanecarboxylates or cis-3-(2-halo-2-trihalomethylethenyl)-2,2-dimethylcyclopropanecarboxylates .

Growing community of inventors

Kanagawa, Japan

Toshiyuki Takashima