Reaktion #574811

Reaktionsgleichung

sodium hydride

trans-3-hydroxy-6-cyano-3,4-dihydro-2,2-dimethyl-4-(1,2-dihydro-2-oxo-4-t-butyldimethylsilyloxymethyl-1-pyridinyl)-2H-benzo[b]pyran

water

→

6-cyano-2,2-dimethyl-4-(1,2-dihydro-2-oxo-4-t-butyldimethylsilyloxymethyl-1-pyridinyl)-2H-benzo[b]pyran

Ausbeute 82.1%

Lösungsmittel

tetrahydrofuran

Reaktionsbedingungen

Aufarbeitung

1. 1
   Sonstigeobtained
2. 2
   Sonstigereacted
3. 3
   Temperaturunder reflux for 4 hours
4. 4
   Sonstigethe reaction
5. 5
   Extraktionthe reaction mixture is extracted with ether
6. 6
   WaschenThe organic layer is successively washed with water and saturated aqueous solution of sodium chloride
7. 7
   Trocknendried over anhydrous sodium sulfate
8. 8
   FiltrationThen, the inorganic matter is filtered off
9. 9
   Einengenthe filtrate is concentrated under reduced pressure
10. 10
    SonstigeThe residue is purified by silica gel column chromatography
11. 11
    workup.ADDITION1/7 mixture of ethyl acetate/methylene chloride as a developing solvent

Vorschrift

In 50 ml of anhydrous tetrahydrofuran, is dissolved 1.32 g of trans-3-hydroxy-6-cyano-3,4-dihydro-2,2-dimethyl-4-(1,2-dihydro-2-oxo-4-t-butyldimethylsilyloxymethyl-1-pyridinyl)-2H-benzo[b]pyran obtained is Example 1. Then, 0.12 g of 60% oily sodium hydride is added to the solution at room temperature and reacted under reflux for 4 hours. After stopping the reaction by adding water, the reaction mixture is extracted with ether. The organic layer is successively washed with water and saturated aqueous solution of sodium chloride and dried over anhydrous sodium sulfate. Then, the inorganic matter is filtered off and the filtrate is concentrated under reduced pressure. The residue is purified by silica gel column chromatography using 1/7 mixture of ethyl acetate/methylene chloride as a developing solvent. Thus, 1.04 g of 6-cyano-2,2-dimethyl-4-(1,2-dihydro-2-oxo-4-t-butyldimethylsilyloxymethyl-1-pyridinyl)-2H-benzo[b]pyran is obtained.

Quelle