Réaction #50178

Équation de réaction

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

pyridinium p-toluenesulfonate

→

4-methoxy-4-(3-hydroxyprop-1-ynyl)tetrahydropyran

Rendement 47.6%

Solvants

methanol

Conditions de réaction

Traitement

1. 1
   AutreThe volatiles were removed in vacuo
2. 2
   workup.DISSOLUTIONthe residue was dissolved in ethyl acetate
3. 3
   workup.ADDITIONtreated with saturated aqueous NH4Cl
4. 4
   SéchageThe organic layer was dried over MgSO4
5. 5
   Filtrationfiltered
6. 6
   Concentrationconcentrated in vacuo
7. 7
   AutrePurification by chromatography on silica gel (100 g, 30% ethyl acetate: hexanes)

Mode opératoire

To a solution of 4-methoxy-4-[3-(tetrahydropyran-2-yloxy)-prop-1-ynyl]tetrahydropyran (3.8 g, 14.8 mmol), prepared as in step 2, in methanol (50 mL), was added a catalytic amount of pyridinium p-toluenesulfonate (PPTS). The resulting yellow solution was stirred under nitrogen for 17 hours at ambient temperature. The volatiles were removed in vacuo and the residue was dissolved in ethyl acetate and treated with saturated aqueous NH4Cl. The organic layer was dried over MgSO4, filtered, and concentrated in vacuo. Purification by chromatography on silica gel (100 g, 30% ethyl acetate: hexanes) provided 4-methoxy-4-(3-hydroxyprop-1-ynyl)tetrahydropyran (1.2 g, 47 %) as a colorless oil.

Source