Methanol → (4s)-5-Cyclopent-1-yl-6-{(r)-hydroxy[4-(trifluoromethyl)phenyl]methyl}-7-isopropyl-2,2-dimethylchroman-4-ol

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Reaction Steps

23 μl (130 μmol) of borane/N,N-diethylaniline complex are added to a solution of 0.1 mg (6.7 μmol) of (1R,2S)-1-aminoindan-2-ol in 1.0 ml of tetrahydrofuran, and the mixture is stirred for 30 min. A solution of 15 mg (33 μmol) of 5-cyclopent-1-yl-6-{hydroxy[4-(trifluormethyl)phenyl]methyl}-7-isopropyl-2,2-dimethyl-2,3-dihydro-4H-chromen-4-one (Example 38A) in 1.0 ml of tetrahydrofuran is then added dropwise, and the mixture is stirred for 2 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. Purification of the crude product by preparative HPLC (method 1) gives the diastereomerically pure target compounds.

Provenance & Evidence