VERFAHREN ZUR HERSTELLUNG VON CYCLOPENTENONEN

摘要

Process for the preparation of cyclopentenones of the general formula I …… in which R<1> to R<4>, independently of one another, denote hydrogen or an organic radical, by reacting carboxylic esters of the general formulae IIa and/or IIb and/or IIc… R<1>CH = CR<2>-CHR<3>-CHR<4>-CO2R<5>     (IIa) and/or… R<1>CH2-CR<2> = CR<3>-CHR<4>-CO2R<5>     (IIb) and/or… R<1>CH2-CHR<2>-CR<3> = CR<4>-CO2R<5>     (IIc),… in which R<1> to R<4> have the abovementioned meanings and R<5> represents C1- to C8-alkyl, over acid heterogeneous catalysts at temperatures of 50 to 800 DEG C and pressures of 0.001 to 50 bar.