Potassium;tri(butan-2-yl)boranuide → cis-Benzyl 4-(2,3-dimethylphenoxy)-3-hydroxypiperidine-1-carboxylate

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Reaction Steps

A solution of benzyl 4-(2,3-dimethylphenoxy)-3-oxopiperidine-1-carboxylate (10.0 g, 28.0 mmol) in tetrahydrofuran (60 ml) was treated at room temperature with K-selectride (10.0M in tetrahydrofuran, 56 ml, 56.0 mmol). On completion of addition the mixture was stirred at room temperature for 18 h. The mixture was concentrated to dryness in vacuo and diluted carefully by addition of ice-water (100 ml). Extraction with dichloromethane (2×200 ml) was followed by washing the combined organics with aqueous hydrochloric acid (100 ml, 0.1N), water (100 ml) and brine (100 ml). The organics were dried over anhydrous magnesium sulfate, filtered and concentrated in vacuo to give a dark oil which was purified by silica gel chromatography using isohexanes:ethyl acetate (5:1) as eluent to furnish cis-benzyl 4-(2,3-dimethylphenoxy)-3-hydroxypiperidine-1-carboxylate as a pale yellow syrup (5.01 g, 50%).

Provenance & Evidence