| 摘要 |
Enol ethers of the general formula I <IMAGE> (I) are prepared by eliminating the radical R4OH from acetals or ketals of the formula II <IMAGE> (II) where the substituents R1 and R2 are each independently of the other hydrogen, C1-C12-alkyl, C3-C8cycloalkyl, C3-C8-cycloalkenyl, unsubstituted or C1-C4-alkyl-substituted aryl or C7-C16 aralkyl, R3 is -CR5(OR4)2, -COOR4 or -COR4, R4 is C1-C20-alkyl, C7-C20-alkylaryl or C7-C20-aralkyl, R5 is hydrogen or C1-C8-alkyl, in a process which comprises performing the reaction in the presence of phosphoric acid and/or phosphates on a carrier material and/or phosphates and/or zeolites as catalysts.
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