Reaktion #50178

Reaktionsgleichung

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

pyridinium p-toluenesulfonate

→

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

Ausbeute 47.6%

Lösungsmittel

methanol

Reaktionsbedingungen

Aufarbeitung

1. 1
   SonstigeThe 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
   TrocknenThe organic layer was dried over MgSO4
5. 5
   Filtrationfiltered
6. 6
   Einengenconcentrated in vacuo
7. 7
   SonstigePurification by chromatography on silica gel (100 g, 30% ethyl acetate: hexanes)

Vorschrift

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.

Quelle