摘要:
Novel syntheses of dihalovinylcyclopropanecarboxylates, including potent insecticides, are described. The processes begin with the reaction between an alkenol and an orthoester to produce a .gamma.-unsaturated carboxylate, followed by the catalyzed addition of a carbon tetrahalide to the double bond and dehydrohalogenation to produce a cyclopropane derivative.
摘要:
A process is described whereby esters of 3-(2,2,2-trichloroethyl)-2,2-dimethylcyclopropane-1-carboxylic acid are prepared predominantly in their cis isomer form. The process comprises treating a 4,6,6,6-tetrachloro-3,3-dimethylhexanoate with an alkali metal tert-alkoxide under controlled conditions of temperature in the presence of a defined solvent-cosolvent mixture. The products of the process are intermediates in the production of pyrethroid insecticides.
摘要:
An improved process for preparing a 6,6,6-trihalo-3,3-dimethyl-4-hexenoate, intermediate in the production of pyrethroid insecticides, comprises dehydrohalogenating with an organic amine a 4,6,6,6-tetrahalo-3,3-dimethylhexanoate having a 4-halogen atom of higher atomic number than any of the 6-halogen atoms.
摘要:
A new process for preparing 1,2-disubstituted-trans-olefins selectively by reacting specific 2-alkenyl phosphonic acid derivatives with metal hydrides, and a new process for producing the specific 2-alkenylphosphonic acid derivatives. The 1,2-disubstituted-trans-olefins are useful as precursors for synthesis of insect pheromones.