Diisopropylethylamine → (2R,3S,5R)-2-(2,2-Dimethylpropoxy)-5-formyl-3-methylmorpholine-4-carboxylic acid tert-butyl ester

Participants

Reaction Steps

Add pyridine sulfur trioxide complex (0.42 g) to (2R,3S,5S)-2-(2,2-dimethylpropoxy)-5-hydroxymethyl-3-methylmorpholine-4-carboxylic acid tert-butyl ester (0.46 g, 1.45 mmol) and N,N-diisopropylethylamine (0.66 g, 5.07 mmol) in dichloromethane (1 mL) and dimethylsulfoxide (4 mL) at −2° C. and stir 30 minutes. TLC shows some alcohol remaining. Add more pyridine sulfur trioxide (100 mg) and stir 30 minutes. Pour into ice-cold saturated aqueous sodium chloride and extract with ethyl acetate. Wash the ethyl acetate layer with 1 N aqueous citric acid, saturated aqueous sodium chloride), dry (magnesium sulfate), filter and concentrate to give the title compound as an oil (456 mg).

Provenance & Evidence