Bicyclo[2.2.1]heptane-1-methanesulfonic acid, 7,7-dimethyl-2-oxo-, (1S)- → (2R,3S,5S)-5-benzyloxymethyl-2-(2,2-dimethylpropoxy)-3-methylmorpholine

Participants

Reaction Conditions

Reaction Steps

Add camphorsulfonic acid (1.69 g, 7.28 mmol) to (R)-3-benzyloxy-2-[(S)-2,2-bis-(2,2-dimethylpropoxy)-1-methylethylamino]-propan-1-ol (1.60 g, 4.04 mmol) in toluene (65 mL) and heat to 100° C. for 1 hour. Cool to room temperature, dilute with ethyl acetate, wash with 2 N sodium hydroxide and saturated aqueous sodium chloride. Dry (magnesium sulfate), filter and concentrate. Purify (silica gel chromatography using deactivated silica gel prepared as previously described, eluting with 10:90 to 70:30 ethyl acetate:hexanes) to give the desired compounds (2S,3S,5S)-5-benzyloxymethyl-2-(2,2-dimethylpropoxy)-3-methylmorpholine (490 mg, 39% top spot,) and (2R,3S,5S)-5-benzyloxymethyl-2-(2,2-dimethylpropoxy)-3-methylmorpholine (495 mg, 40% bottom spot).

Provenance & Evidence