反应详情

温度

-50 °C

To a cooled (-50° C.) stirred solution of 27.7 g of 2-bromobenzhydryl methyl ether in 80 ml of dry tetrahydrofuran is added dropwise under nitrogen 60 ml of 2.4 M n-butyllithium in hexane. The mixture is stirred for 2 hours and a solution of 15.9 g of 1,4-dioxaspiro[4.5]decan-8-one in 50 ml of dry tetrahydrofuran is added dropwise, maintaining the temperature at -40° to -30° C. The mixture is stirred overnight at -70° to +10° C., diluted with 100 ml of water and extracted with 100 ml of dichloromethane. The organic phase is washed with water (2×50 ml), dried over anhydrous sodium sulfate and concentrated in vacuo. A solution of the residue in 400 ml of ethanol is stirred with 50 ml of hydrogen bromide/ether at room temperature for 3 hours. The solvent is removed under reduced pressure and the remaining oil crystallizes from 100 ml of methanol to give 39.6% of product, mp 130°-132° C.

1. temperaturemaintaining the temperature at -40° to -30° C
2. stirringThe mixture is stirred overnight at -70° to +10° C.
3. extractionextracted with 100 ml of dichloromethane
4. washThe organic phase is washed with water (2×50 ml)
5. dry with materialdried over anhydrous sodium sulfate
6. concentrationconcentrated in vacuo
7. stirringA solution of the residue in 400 ml of ethanol is stirred with 50 ml of hydrogen bromide/ether at room temperature for 3 hours
8. customThe solvent is removed under reduced pressure
9. customthe remaining oil crystallizes from 100 ml of methanol