Potassium bis(trimethylsilyl)amide → Boc-1(S)-cyclohexylmethylprop-2-en-1-ylamine

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Reaction Conditions

Reaction Steps

A 0° C. solution of potassium hexamethyldisilazide (22.9 mmol in 115 mL of 5:1, tetrahydrofuran (THF): dimethyl sulfoxide (DMSO) was added dropwise to triphenylmethylphosphonium iodide (24.81 mmol). After stirring at 0° C. for 1 hour, the solution was cooled to -78° C. and a solution of Boc-cyclohexylalaninal [4.90 g, 19.08 mmol, prepared by Swern oxidation (Mancuso, A. J.; Huang,, S. -L.; and Swern, D., J. Org. Chem. 1978, 43, 2480) of Boc cyclohexylalaninol] in dry THF (95 mL) was added. After stirring at -78° C. for 1 hour, the mixture was allowed to warm to room temperature. The reaction mixture was quenched with aqueous ammonium chloride and extracted with ether (2×300 mL). The combined organic phase was washed with 10% HCl (200 mL), saturated NaHSO3 (2×200 mL), H2O (2×200 mL), saturated NaHCO3 (2×200 mL), and brine (200 mL), dried (MgSO4), filtered, and evaporated. The residue was purified by chromatography (40 m SiO2 ; ether:hexane, 15:85) to give the desired compound in 60% yield. Mass spectrum: (M+H)+ =254.

Provenance & Evidence