Dimethyl Sulfoxide → tert-Butyl (2S,4R)-4-((tert-butyldimethylsilyl)oxy)-2-formylpyrrolidine-1-carboxylate

Participants

Reaction Steps

To a solution of oxalyl chloride (0.16 mL; 1.785 mmol) in CH2Cl2 (2 mL) at −78° C. was added DMSO (0.25 mL; 3.55 mmol) dropwise and the mixture was stirred for 10 min. The mixture was then treated with a solution of Compound 27c (395 mg; 1.19 mmol) in CH2Cl2 (3 mL) dropwise and continually stirred for 20 min. To the resultant mixture was added Et3N (0.5 mL; 3.55 mmol) dropwise and the mixture was stirred at −78° C. for 30 min. The mixture was allowed to warm to ambient temperature while continually stirring over 20 min. The reaction mixture was quenched with saturated NH4Cl (aq), extracted with EtOAc, washed with water and brine; and the combined organic extracts were dried over Na2SO4, and concentrated under reduced pressure to give the crude material. The crude material was purified by flash column chromatography (SiO2), eluting with a heptane-EtOAc gradient to afford Compound 27d (250 mg; 64% yield). 1H-NMR (400 MHz, CDCl3): δ 9.44-9.57 (m, 1H), 4.20-4.39 (m, 1H), 3.35-3.57 (m, 1H), 1.89-2.09 (m, 1H), 1.44-1.49 (m, 9H), 0.88 (s, 9H), 0.08 (s, 6H); MS: m/z 330.2 (M+H)+.

Provenance & Evidence