반응 #50176

반응 방정식

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

수율 88.3%

용매

THF

반응 조건

후처리

1. 1
   기타The reaction was quenched by addition of crushed ice and saturated aqueous NH4Cl
2. 2
   추출The resulting two-layered mixture was extracted with ether (3×150 mL)
3. 3
   건조The combined organic layers were dried over MgSO4
4. 4
   여과filtered
5. 5
   농축concentrated in vacuo
6. 6
   기타Purification by chromatography on silica gel (200 g, 20% ethyl acetate: hexanes)

실험 절차

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%).

출처