2-Chloro-4-tri:bromo:ethyl-cyclo:butanone derivs. - prepd. from substd. butyryl chloride and olefin, used as insecticide intermediates

摘要

New cyclobutanone derivs. of formula (I) are prepd. by reacting a new butyric acid deriv. of formula Br3CCH2CHClCOCl (II) with an olefin of formula CH2=CR1R2 (III) in presence of an organic base. The obtd. new cpd. of formula (IV) is catalytically rearranged to give (I): In the formulae, one of R1 and R2 is Me and the other is H or Me, or R1+R2 is 2-4C alkylene. (Ie are intermediates for insecticidal 2-(2,2-dibromovinyl)-cyclopropane carboxylic acid derivs.