Hydrochloric Acid → 3-Boc-2,2-dimethyloxazolidine-4-carboxaldehyde, (R)-(+)-

Participants

Reaction Conditions

Reaction Steps

To a −78° C. solution of (R)-3-tert-butyl 4-methyl 2,2-dimethyloxazolidine-3,4-dicarboxylate (Intermediate 181, 18.80 g, 72.50 mmol) in toluene (153 mL) was dropwise (via addition funnel) added DIBAL-H (1.0 M in toluene) (116 ml, 116.01 mmol) over 1.5 hours. The reaction mixture was stirred at −78° C. for 2 hours under nitrogen atmosphere. The cold reaction mixture was treated with 38 mL MeOH (˜1.91 M) and then poured 750 mL cold 1N HCl (˜0.09M) into reaction mixture, removed reaction mixture from −78° C. bath, transferred to separatory funnel and extracted with ethyl acetate. The organic layers were dried over magnesium sulfate, filtered, concentrated. Due to a difficult separation required two silica gel chromatography columns (0%-50% ethyl acetate/hexanes) to afford the title compound as a colorless oily solid (10.2 g, 61%).

Provenance & Evidence