| 摘要 |
PURPOSE:To obtain economically and advantageously the titled compound which is not easily produced, by reacting a beta-keto-acid with acetone in the presence of an acid catalyst and acetic anhydride, etc. CONSTITUTION:A beta-keto-acid of formula I (R1 is alkyl, aryl or aralkyl; R2 is H, alkyl, aryl or aralkyl; R3 is H) is reacted with acetone in the presence of an acid catalyst, e.g. concentrated sulfuric acid, and acetic anhydride or ketene or reacted with isopropenyl acetate of the formula CH2=C(Me)-O-COMe to give the aimed compound of formula II.
|
