反应详情

(S)-1-(tert-Butoxy)-3-cyclohexyl-propan-2-ol was prepared according to the procedure described by Alan Armstrong et al., Tetrahedron Letters 1988, 29: 2483-2486. Three drops of boron trifuoride etherate were added to a solution of (S)-3-cylcolhexyl 1,2-propanediol (540 mg, 3.4 mmol) and tert-butyl 2,2,2-trichloroacetamide (670 μL, 3.8 mmol) in cyclohexane (7 mL) at ambient temperature. After stirring for 21 hours, a saturated solution of NaHCO3 was added to the reaction mixture and the mixture was extracted with EtOAc (2×). The EtOAc phases were combined, dried (MgSO4) and concentrated. The residue was chromatographed (silica gel; EtOAc/hexanes, 1:10) to afford a clear oil (235 mg, 32%). 1H NMR (CDCl3, 300 MHz) δ0.79-1.01 (m, 2H), 1.12-1.53 (m, 6H), 1.20 (s, 9H) 1.58-1.84 (m, 5H), 3.12 (dd, J=9, 9 Hz, 1H), 3.35 (dd, J=3, 9 Hz, 1H), 3.81 (m, 1H); MS (CI/NH3) m/z: (M+H)+ 215.

1. extractionthe mixture was extracted with EtOAc (2×)
2. dry with materialdried (MgSO4)
3. concentrationconcentrated
4. customThe residue was chromatographed (silica gel; EtOAc/hexanes, 1:10)