| 摘要 |
Prepn. of 2-pentylcyclopent-2-en-1-one (I) is effected by reaction of 1-heptyne and ethylene in presence of a catalytic amt. of (CO2(CO)8) (II) and under elevated pressure of CO and ethylene, at 120-160 deg.C. Pref. (II) is used together with (Fe(CO)5). The partial pressure of CO (greater than 4MPa) and that of ethylene (4-5 MPa) are sufficient to ensure a 1-heptyne/CO molar ratio of 1:2-1:8 and a 1-heptyne/ethylene molar ratio of 1:5-1:10. Amt. of (II) is 0.10-2.0 mole % w.r.t. 1-heptyne. Ratio of (II) to (Fe(CO)5) is 1:1-1:2. In a pref. process, reaction is at 150 deg.C, in presence of 0.0875 mmole of (II) for a concn. 0.8M in 1-heptyne, the partial pressures of CO and ethylene, measured at r.t., being resp. 100 and 4 MPa, or reaction is at 150 deg.C in presence of 0.0438 mmole of (II) and 0.0875 mmole (Fe(CO)5) for a concn. 0.8M in 1-heptyne, the partial pressures of CO and ethylene, measured at room temp. being 100 and 4 MPa respectively. USE/ADVANTAGE - (I) is an intermediate for synthesis and in partic. is a precursor of methyl dihydrojasmonate which is used in perfumery. The above prepn. gives (I) in good yields under reaction conditions utilisable on an industrial scale
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