Reaktion #41292

Reaktionsgleichung

tert-butyl[(1S)-2-(4-ethylphenyl)-1-methyl-2-oxoethyl]carbamate

Al(iPr)3

2-propanol

→

subtitle compound

tert-Butyl[(1S,2R)-2-(4-ethylphenyl)-2-hydroxy-1-methylethyl]carbamate

Lösungsmittel

toluene

Reaktionsbedingungen

Aufarbeitung

1. 1
   TemperaturThen the reaction mixture was cooled to r.t.
2. 2
   Sonstigequenched with aqueous HCl (1 N, 10 ml)
3. 3
   workup.ADDITIONdiluted with ethyl acetate (10 ml)
4. 4
   SonstigeThe layers were separated
5. 5
   Waschenthe organic layer was washed with water (80 ml)
6. 6
   Trocknendried with Na2SO4
7. 7
   Einengenconcentrated

Vorschrift

The procedure described by J. Yin et al., J. Org. Chem. 2006, 71, 840-843) was used. A mixture of tert-butyl[(1S)-2-(4-ethylphenyl)-1-methyl-2-oxoethyl]carbamate (555 mg, 2 mmol), Al(iPr)3 (81 mg, 0.4 mmol), 2-propanol (1.32 g, 22 mmol), and toluene (2.6 ml, 1.3 ml/mmol) was heated in a sealed vial at 50° C. overnight. Then the reaction mixture was cooled to r.t., quenched with aqueous HCl (1 N, 10 ml), and diluted with ethyl acetate (10 ml). The layers were separated, the organic layer was washed with water (80 ml), dried with Na2SO4, and concentrated. Trituration with n-heptane (30 ml) afforded the subtitle compound as colourless precipitate, 137 mg. n-Heptane solution was concentrated under reduced pressure, and the residue purified by flash chromatography in silica gel to give the second crop of the subtitle compound, 318 mg. Overall yield 455 mg (81%).

Quelle