Dimethyl Sulfoxide → 3-(tert-Butyldimethylsilanyloxy)-2-formylpyrrolidine-1-carboxylic acid tert-butyl ester

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

A solution containing 2M oxalyl chloride in DCM (22 mL) in DCM (40 mL) was cooled to −78° C. A solution containing DMSO (3.2 mL, 45 mmol) in DCM (20 mL) was added in a dropwise fashion. After 45 min, alcohol 40 (9.5 g, 29 mmol) in DCM (50 mL) was added in a dropwise fashion. After 45 min, TEA (16 mL, 115 mmol) was added in a dropwise fashion. The reaction mixture was warmed and maintained at 0° C. for 15 min. The solution was diluted with 1M HCl, extracted with DCM, washed with brine, dried over anhydrous Na2SO4, filtered, and concentrated to afford 9.5 g (100%) of 41 as a yellow oil. 1H NMR (CDCl3, 300 MHz) δ9.53 (d, J=29 Hz, 1H), 4.39-4.36 (m, 1H), 4.24 (m, rotomer, 0.5H), 3.93 (m, rotomer, 0.5H), 3.73-3.49 (m, 2H), 1.98-1.86 (m, 2H), 1.47 (s, minor rotomer), 1.41 (s, 9H), 0.88 (s, 9H), 0.09 (s, 6H), 0.07 (s, minor rotomer) ppm.

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