Dimethyl Sulfoxide → (R)-2-(Trityl-amino)-butyraldehyde

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

To a stirred solution of DMSO (3.0 mL, 42.28 mmol) in CH2Cl2 (30 mL) under Ar at −45° C., was added oxalyl chloride (2 M in CH2Cl2, 10.56 mL, 21.12 mmol) dropwise. The reaction mixture was stirred at −45° C. for 1 h, after which time a solution of (R)-2-(trityl-amino)-butan-1-ol (5 g, 15.08 mmol) in CH2Cl2 (30 mL) was added dropwise with stirring. The reaction mixture was sired at this temperature for 3 h, when TLC (8:2 hexane/Et2O) indicated that the reaction had gone to completion. Et3N (10.5 mL, 75.33 mmol) in CH2Cl2 (30 mL) was added and the solution was allowed to warm to RT over 16 h. It was diluted with more CH2Cl2 (200 mL) and washed with H2O (250 mL). The aqueous phase was extracted with CH2Cl2 (3×50 mL) and the combined organic phases washed with brine (50 mL), dried (MgSO4), and evaporated in vacuo. The residue was dissolved in Et2O (30 mL), the solid precipitate was removed by filtration, and the filtrate was evaporated in vacuo. The residue was dissolved in hexane (50 mL), the solid precipitate was removed by filtration, and the filtrate was evaporated in vacuo to afford the title compound as a light yellow oil (2.59 g, 52%). 1H-NMR (d6-DMSO, 250 MHz): δ 0.77 (t, 3H, J=7.42 Hz, —NHCH(CH2CH3)CHO), 1.34-1.61 (m, 2H, —NHCH(CH2CH3)CHO), 2.92 (m, 1H, —NHCH(CH2CH3)CHO), 3.62 (d, 1H, J=8.21 Hz, —NHCH(CH2CH3)CHO), 7.16-7.46 (m, 15H, 3×Bz), 8.77 (d, 1H, J=3.00 Hz, —NHCH(CH2CH3)CHO).

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