反应详情

温度

-40 °C

28.5 g of methyltriphenylphosphonium bromide are suspended under nitrogen in 300 ml of anhydrous THF and the mixture is cooled to -40° C. 50 ml of n-butyllithium (1.6M) in n-hexane are then added dropwise with stirring. After stirring at -20° to -10° for 30 min, a solution of 20 g of methyl 4-methoxy-3-(2-oxocyclopentyloxy)benzoate in 100 ml of abs. THF is added dropwise. The mixture is then allowed to warm to RT and is stirred for a further 1 h. It is poured onto water and extracted with ethyl acetate. The oil which remains after concentrating the organic phase is chromatographed on a silica gel column using ethyl acetate/petroleum ether (4:6). The chromatographically pure fractions are combined, concentrated and dried in a high vacuum. 12.7 g of the title compound are obtained as a colorless oil.

1. stirringAfter stirring at -20° to -10° for 30 min
2. temperatureto warm to RT
3. stirringis stirred for a further 1 h
4. additionIt is poured onto water
5. extractionextracted with ethyl acetate
6. concentrationafter concentrating the organic phase
7. customis chromatographed on a silica gel column
8. concentrationconcentrated
9. customdried in a high vacuum