反应详情

903 mg (23.8 mmol) of lithium aluminium hydride are initially introduced in 20 ml of THF, and a solution of 10 g (23.8 mmol) of ethyl 5-propyl-2-(3′,4′,5′-trifluoro-3-hydroxybiphenyl-4-yl)cyclohexanecarboxylate in 50 ml of THF is added dropwise with ice-cooling. The cooling is removed, and the batch is stirred at room temp. for 3 h, refluxed for 1 h and added to ice. After acidification using 2M sulfuric acid, the mixture is extracted three times with MTB ether, the combined org. phases are washed with water and dried over sodium sulfate. The solvent is removed under reduced pressure, and the residue is purified by chromatography on silica gel. The 3′,4′,5′-trifluoro-4-(2-hydroxymethyl-4-propylcyclohexyl)biphenyl-3-ol obtained is dissolved in 100 ml of THF, 6.24 g (23.8 mmol) of triphenylphosphine are added, and a solution of 5.3 g (26.2 mmol) of diisopropyl azodicarboxylate in 50 ml of THF is added dropwise with ice-cooling. The cooling is removed, and the batch is stirred at room temp. overnight. After addition of water, the organic phase is separated off, and the aqueous phase is extracted three times with MTB ether. The combined org. phases are washed with water and saturated sodium chloride solution and dried over sodium sulfate. The solvent is removed under reduced pressure, and the residue is purified by chromatography on silica gel, giving 8-propyl-3-(3,4,5-trifluorophenyl)-6a,7,8,9,10,10a-hexahydro-6H-benzo[c]chromene as colourless crystals.

1. temperaturecooling
2. customThe cooling is removed
3. temperaturerefluxed for 1 h
4. additionadded to ice
5. extractionthe mixture is extracted three times with MTB ether
6. washphases are washed with water
7. dry with materialdried over sodium sulfate
8. customThe solvent is removed under reduced pressure
9. customthe residue is purified by chromatography on silica gel