反应 #50176

反应方程式

Tetrahydro-2-(2-propynyloxy)-2H-pyran

tetrahydro-4H-pyran-4-one

ethyl magnesium bromide

→

4-hydroxy-4-[3-(tetrahydropyran-2-yloxy)prop-1-ynyl]tetrahydropyran

收率 88.3%

溶剂

THF

反应条件

后处理

1. 1
   其他The reaction was quenched by addition of crushed ice and saturated aqueous NH4Cl
2. 2
   萃取The resulting two-layered mixture was extracted with ether (3×150 mL)
3. 3
   干燥The combined organic layers were dried over MgSO4
4. 4
   过滤filtered
5. 5
   浓缩concentrated in vacuo
6. 6
   其他Purification by chromatography on silica gel (200 g, 20% ethyl acetate: hexanes)

实验过程

Tetrahydro-2-(2-propynyloxy)-2H-pyran (21 g, 150 mmol) was converted to the corresponding magnesium anion by deprotonation with ethyl magnesium bromide (75 mL of a 2M solution, 150 mmol) according to the method described in Org. Synth., 60: 81, 7 (1981). The resulting anion was cooled to -20° C. and tetrahydro-4H-pyran-4-one (14.8 g, 148 mmol) in dry THF (30 mL) was added dropwise and the resulting solution stirred for three hours. The reaction was quenched by addition of crushed ice and saturated aqueous NH4Cl. The resulting two-layered mixture was extracted with ether (3×150 mL). The combined organic layers were dried over MgSO4, filtered, and concentrated in vacuo. Purification by chromatography on silica gel (200 g, 20% ethyl acetate: hexanes) provided 4-hydroxy-4-[3-(tetrahydropyran-2-yloxy)prop-1-ynyl]tetrahydropyran(31.4 g, 88%).

来源