反应详情

温度

0 °C

4(RS)-t-butyldimethylsilyloxy-2-cyclopentenone (2.12 g; 10 mmoles) was dissolved in 25 ml of methanol. The solution was cooled to 0° C., and 30% aqueous hydrogen peroxide (5 ml; 45 mmoles) was added. Several drops of a 2N aqueous solution of sodium hydroxide were added, and the mixture was stirred for 30 minutes. The methanol was distilled off under reduced pressure. Water was added to the residue and the mixture was extracted with ether. The extract was dried over magnesium sulfate, and concentrated under reduced pressure to give 4(RS)-t-butyldimethylsilyloxy-2,3-epoxycyclopentanone as a crude product. The crude product was dissolved in 20 ml of methanol, and a solution of 1.62 g (10 mmoles) of methyl 6-mercaptohexanoate in 10 ml of methanol was added. Furthermore 1 ml of triethylamine was added. The mixture was stirred at room temperature for 18 hours in an atmosphere of nitrogen. After the reaction, the reaction mixture was concentrated under reduced pressure. The residue was chromatographed on a silica gel column using hexane/ethyl acetate (6/1) as an eluent to give 2.24 g (6.02 mmoles; 60.2%) of 4(RS)-t-butyldimethylsilyloxy-2-(5-methoxycarbonylpentylthio)-2-cyclopentenone.

1. distillationThe methanol was distilled off under reduced pressure
2. additionWater was added to the residue
3. extractionthe mixture was extracted with ether
4. dry with materialThe extract was dried over magnesium sulfate
5. concentrationconcentrated under reduced pressure