Allyl bromide → Tert-butyl 4-allyl-4-hydroxypiperidine-1-carboxylate

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Reaction Steps

A dry round bottom flask was purged with nitrogen and charged with 1-t-butoxycarbonyl-4-piperidinone (20 g, 100 mmol), titanocene dichloride (1.2 g, 5 mmol) and zinc dust (7.8 g, 120 mmol) in 100 mL dry THF. Allyl bromide (11.3 mL, 130 mmol) was added and the mixture was stirred for 5 h at rt. The mixture was diluted with 700 mL EtOAc, washed with 2.0 M HCl (2×200 ML), 100 mL of sat'd NaCl, dried over MgSO4 and concentrated. Flash chromatography (650 g silica, 10/1 CH2Cl2/Et2O eluant) afforded 10.9 g (45%) of the title compound: 1H NMR (300 MHz) δ 1.4-1.6 (13H), 2.2-2.25 (d, 2H), 3.1-3.2 (m, 2H), 3.75-3.85 (m, 2H), 5.1-5.25 (m, 2H), 5.78-5.92 (m, 1H).

Provenance & Evidence