PURPOSE: To obtain the titled compound useful as an intermediate of insecticide, etc., easily, by the dehydration, alcohol-removal, or decarboxylation reaction of 1,1,1-tribromo-4-methyl-4-pentanol or its derivative in the presence of an acid catalyst.
CONSTITUTION: The compound of formulaI(R1 is H, alkyl, cycloalkyl, aryl, aralkyl, or acyl) is subjected to dehydration reaction, alcohol-removal reaction or decarboxylation reaction in the presence of an acid catalyst such as p-toluenesulfonic acid to afford the compound of formula II (Z is group of formula III or IV). The compound of formula II wherein Z is group of formula IV can be isomerized to another compound of formula II wherein Z is group of formula III by heating in the presence of a catalyst such as pd. A cyclopropane-carboxylic acid ester useful as a raw material of synthetic pyrethroid can be prepared from the compound in high yield, by a process simpler than conventional method, by reacting the compound with a diazoacetic acid ester by conventional process, and then subjecting to the dehydrobromination reaction.
OOMURA SUKEAKI
MORI FUMIO
ITOI KAZUO
NISHIDA TAKUJI
TAMAI HIRONOBU
AIHARA FUKUJI
HOSOGAI TAKEO
WADA TOMIO
