Cerium(III) chloride → tert-Butyl (3S,6S)-6-{[(tert-butyldimethylsilyl)oxy]methyl}-3-hydroxy-4-methyl-1,2,3,6-tetrahydropyridine-1-carboxylate

Participants

Reaction Steps

To a solution of cerium(III) chloride (14.68 g, 59.57 mmol) and (S)-tert-butyl 2-((tert-butyldimethylsilyloxy)methyl)-4-methyl-5-oxo-5,6-dihydropyridine-1(2H)-carboxylate (Intermediate 7, 21.18 g, 59.57 mmol) in methanol (300 mL) at 0° C. was added sodium borohydride (2.254 g, 59.57 mmol) portionwise. After 15 minutes, the reaction mixture was diluted with saturated ammonium chloride (100 mL) and water (100 mL), then extracted twice with diethyl ether. The organic extracts were washed with brine, dried over magnesium sulfate, filtered and concentrated. Silica gel chromatography (0%-20% ethyl acetate/hexanes) afforded the desired product (19.45 g, 91%) as a colorless oil.

Provenance & Evidence