NEW MATERIAL:Compds. expressed by formula I [R is lower alkyl, R1 is formula II (R2=R), formula III or formul IV (R3s are R or together form alkylene or polymethylene group)].
EXAMPLE: Methyl 5,5-dimethoxy-3,3-dimethylpentanoate.
USE: A raw material for 5-oxo-3,3-dimethylpentanoic esters useful as a starting material for insecticides such as permethrin.
PREPARATION: A 3,3-dimethyl-4-pentanoic ester expressed by formula V, and carboxylic acid expressed by the formula R2COOH such as acetic acid are reacted in the presence of oxygene and a Pd catalyst such as palladium acetate, at room temp. W 150°C, to form compds. expressed by formula I (R1 is formulas II and III). The resultant products are reacted with an alcohol expressed by the formula R3OH such as methanol in the presence of an acetalizing catalyst such as p-toluenesulfonic acid at room temp. W 100°C to obtain the compd. expressed by formula I (R1 is formula IV).
URATA HISAO
TANAKA MARIKO
KONDO SEI
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