(+/-)-(2S,3R)-1-tert-Butoxycarbonyl-3-(tert-butyldimethylsilanyloxy)pipecolic acid methyl ester → (+/-)-(2S,3R)-1-tert-Butoxycarbonyl-3-(tert-butyldimethylsilanyloxy)-2-hydroxymethylpiperidine

Participants

Reaction Steps

To a solution of 77D (1.0 g, 2.7 mmol) in THF (10 mL) at −78° C. was added a solution of LiEt3BH (1.0 M in THF, 13.5 mL, 13.5 mmol, 5 equiv). The mixture was warmed to rt and stirred at rt for 4 h. The mixture was poured over ice and stirred vigorously for 15 min. The mixture was extracted with EtOAc (2×50 mL). The combined organic layers were washed with 0.5 N HCl (20 mL), saturated sodium bicarbonate solution (20 mL), brine (20 mL), dried (MgSO4) and evaporated to give the crude product as a colorless oil. Purification of the crude product by flash chromatography (5-50% EtOAc/hexane) gave the desired product 77E (960 mg): Rf (50% EtOAc/hexane) 0.64; HPLC (Phenomenex Luna 5 u C18 4.6×50 mm, linear gradient over 4 min) retention time 4.1 min (100%); MS (ES) m/z 346.1 [M+1]+; HRMS calcd for C17H36NO4Si 346.2414, Found 346.2419.

Provenance & Evidence