Methanol → Rac-5-cyclopent-1-yl-6-{hydroxy[4-(trifluoromethyl)phenyl]methyl}-7-isopropyl-2,2-dimethyl-2,3-dihydro-4h-chromen-4-one

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Reaction Steps

155 μl (872 μmol) of borane/N,N-diethylaniline complex are added slowly to a solution of 4.9 mg (33 μmol) of (1R,2S)-1-aminoindan-2-ol in 5.0 ml of tetrahydrofuran, and the mixture is stirred for 30 min. A solution of 100 mg (218 μmol) of 5-cyclopent-1-en-1-yl-6-{hydroxy[4-(trifluoromethyl)phenyl]methyl}-7-isopropyl-2,2-dimethyl-2,3-dihydro-4H-chromen-4-one (Example 36A) in 5.0 ml of tetrahydrofuran is then, very slowly, added dropwise, and the mixture is stirred for 4 h. Methanol is then added, and the mixture is concentrated under reduced pressure. The residue is taken up in ethyl acetate and washed in each case twice with 1 M hydrochloric acid and saturated sodium bicarbonate solution and once with saturated sodium chloride solution. The organic phase is dried over sodium sulfate and then concentrated under reduced pressure. The crude product is purified by preparative HPLC (method 1). In addition to the title compound, the compounds described as Preparation Examples 22 and 23 are also isolated (for yield and analytical data see there).

Provenance & Evidence