反应详情

温度

-78 °C

A solution of 1 g (tetrahydro-pyran-4-yl)-acetic acid ethyl ester [103260-44-2] in 3 ml of dry tetrahydrofuran is added dropwise to a solution of lithium diisopropyl amide (freshly prepared from 1 ml diisopropyl amine and 4.3 ml 1.6 M butyllithium solution in hexanes) in 5 ml of dry tetrahydrofuran at −78° C. The reaction mixture is stirred for 15 minutes at −78° C. and then 0.46 ml of methyl iodide are added and the mixture is allowed to warm to 0° C. over a period of 15 minutes. The reaction mixture is re-cooled to −78° C. and then a solution of lithium diisopropyl amide (freshly prepared from 1 ml diisopropyl amine and 4.3 ml 1.6 M butyllithium solution in hexanes) in 5 ml of dry tetrahydrofuran is added dropwise. The solution is stirred for 15 minutes at −78° C. and then 0.46 ml of methyl iodide are added and the mixture is allowed to warm to room temperature. After 2 hours, the reaction mixture is quenched with 20 ml of 1M HCl and then extracted with tert-butyl methyl ether (2×). The combined organic phases are washed with brine, dried over sodium sulphate and concentrated by evaporation. The title compound is obtained as a colourless oil from the residue by means of flash chromatography (SiO2 60F). Rf=0.27 (1:5 EtOAc-heptane).

1. temperatureto warm to 0° C. over a period of 15 minutes
2. temperatureThe reaction mixture is re-cooled to −78° C.
3. additionis added dropwise
4. stirringThe solution is stirred for 15 minutes at −78° C.
5. temperatureto warm to room temperature
6. waitAfter 2 hours
7. customthe reaction mixture is quenched with 20 ml of 1M HCl
8. extractionextracted with tert-butyl methyl ether (2×)
9. washThe combined organic phases are washed with brine
10. dry with materialdried over sodium sulphate
11. concentrationconcentrated by evaporation