Dimethyl Sulfide → (2r,3s)-3-(Tritylamino)pentan-2-ol

Participants

Reaction Steps

To a stirred suspension of CuBr.SMe2 (2.74 g, 13.33 mmol) in Et2O (100 mL) under Ar at −70° C., was added methyl lithium (1:6 M in Et2O; 15.13 mL, 24.21 mmol) dropwise and the solution allowed to warm to RT. The mixture was re-cooled to −70° C., to which was added a solution of (S)-2-(trityl-amino)-butyraldehyde (2 g, 6.05 mmol) in Et2O (25 mL) dropwise with stirring. The reaction mixture was stirred at this temperature for 2 h and then at −55° C. for 4 h, when TLC (8:2 hexane/Et2O) indicated that the reaction had gone to completion. To the reaction mixture was added a saturated aqueous solution of NH4Cl (100 mL) and allowed to warm to RT over 16 h. The reaction mixture was extracted with Et2O (2×200 mL), and the combined organic phase washed with brine (50 mL), dried (MgSO4) and evaporated in vacuo. The residue was purified by silica gel column chromatography, eluted with hexane/Et20 (8:2) to afford the title compounds as a light yellow oil (1.37 g, 66%). 1H-NMR (d6-DMSO, 250 MHz): δ 0.44-0.58 (m, 3H, —NHCH(CH2CH3)CH(CH3)OH), 0.99-1.12 (m, 5H, —NHCH(CH2CH3)CH(CH3)OH+—NHCH(CH2CH3)CH(CH3)OH), 2.01 (m, 1H, —NHCH(CH2CH3)CH(CH3)OH), 3.22-3.43 (m, 1H, —NHCH(CH2CH3)CH(CH3)OH), 4.41 (d, 1H, J=3.31 Hz, —NHCH(CH2CH3)CH(CH3)OH), 7.14-7.56 (m, 15H, 3×Bz).

Provenance & Evidence