tert-Butyl 3-oxo-8-azabicyclo(3.2.1)octane-8-carboxylate → tert-Butyl 3-hydroxy-8-azabicyclo[3.2.1]octane-8-carboxylate

関与物質

反応条件

反応手順

NaBH4 (8.8 g, 0.23 mol) was added to a 0° C. solution of 3-oxo-8-azabicyclo[3.2.1]octane-8-carboxylic acid tert-butyl ester (35 g, 0.16 mol) in ethanol (200 ml). The reaction mixture was stirred for 45 min at 0° C., whereupon it was allowed to reach 20° C. After stirring overnigth the suspension was evaporated to dryness. EtOAc (350 ml) was added, and the precipitate was filtered off. Water (200 ml) was added to the filtrate, and the layers were separated. The aqueous layer was extracted with EtOAc (100 ml), and the combined organic layers were dried (Na2SO4) and concentrated in vacuo to afford 29.5 g of an oil, which crystallised on standing. The two isomers were separated by flash chromatography (EtOAc/heptane 1:5 □ 1:1), affording 5 g of the title compound. LC-MS (m/z): 250 (M+23(Na)).

情報源と証拠