反应详情

2 parts of [(tetrahydro-2H-pyran-2-ylidene)methyl] triphenylphosphonium chloride and 0.82 part of 4-methylbenzaldehyde were combined in 45 parts of xylene. This suspension was maintained under a nitrogen atmosphere and was refluxed for 4.5 hours to produce a clear solution. After the solution was cooled to room temperature, the xylene was removed at a temperature of about 40° C., under reduced pressure to yield a product mixture. This mixture was separated chromatographically on a silica column using as an elution solvent increasing concentrations of ethyl acetate in toluene, to yield 1-(4-methylphenyl)-7-chloro-1-hepten-3-one in the fraction containing 1.5 percent by volume of ethyl acetate in toluene which, after recrystallization from cyclohexane, melted at about 79°-82° C.

1. temperatureThis suspension was maintained under a nitrogen atmosphere
2. temperaturewas refluxed for 4.5 hours
3. customto produce a clear solution
4. customthe xylene was removed at a temperature of about 40° C., under reduced pressure
5. customto yield a product mixture
6. customThis mixture was separated chromatographically on a silica column
7. temperatureincreasing concentrations of ethyl acetate in toluene