| 摘要 |
Unsaturated aldehydes, ketones and acids and esters of unsaturated alcohols with carboxylic acids are prepared by contacting an unsaturated compound <FORM:1101056/C2/1> in which each R1, R2, R3 and R4 is a hydrogen atom or a saturated alkyl (not more than 8C), or any two of R1, R2, R3 and R4 are combined as a divalent saturated alkyl group, and Y is an acyloxy, aroyloxy or hydroxy group or a chlorine or bromine atom, with a palladium salt in the presence of an aliphatic carboxylic acid containing between 2 and 10 carbon atoms, molecular oxygen and a salt of copper or iron either under anhydrous conditions or in the presence of not more than 20% of water, any halide ions present being chlorine or bromine ions in concentration not exceeding 0.35 molar. Palladium acetate, or preferably a palladium halide may be used and preferably carboxylate (2-10 C) ions are present additional to those provided by the ionization of the carboxylic acid. Processes mentioned use allyl acetate to yield allylidene diacetate which may be hydrolysed to acrolein, and allyl chloride or allyl alcohol to form acrolein; methylallyl acetate to prepare methacrolein; crotyl acetate to form crotonaldehyde; a -methyl allyl acetate to form methyl vinyl ketone; g -ethyl allyl acetate to form b -ethyl acrolein; and 1-cyclohexene-3-acetate to form 1-cyclohexen-3-one. Mixed products may be formed depending upon the reaction conditions. Examples describe the preparation of mixed products allylidene diacetate, acrolein, and propylene 1-acetate. |
