Lithium tri-s-butylborohydride → HCID 57987375, compound

Participants

Reaction Conditions

Reaction Steps

L-Selectride® (1.0 M in THF, 1.4 ml, 1.4 mmol) was added slowly to a stirred solution of the enone (Step 1, 538 mg, 1.35 mmol) in dry THF (10 ml) under N2, such that the internal temperature was kept below −70° C. The reaction was maintained at −78° C. for 1 hour, then quenched with saturated aqueous NH4Cl solution. After warming to room temperature the mixture was partitioned between EtOAc/H2O. The layers were separated and the aqueous layer was further extracted with EtOAc (×2). The combined extracts were washed with brine (×1), dried (Na2SO4), filtered and evaporated. The residue was purified by chromatography on silica, eluting with 5-10% EtOAc/isohexane to give the ketone (458 mg, 85%) as an oil. 1H NMR (500 MHz, CDCl3) δ: 1.21 (6H, d, J 6.9), 2.48 (2H, t, J 7.0), 2.56-2.62 (1H, m), 2.67-2.73 (1H, m), 2.78-2.85 (1H, m), 2.98-3.00 (1H, m), 3.47-3.53 (1H, m), 3.65-3.71 (1H, m), 4.95 (1H, d, J 3.3), 5.03 (1H, dd, J 17.0, 1.3), 5.10 (1H, d, J 9.2), 5.75-5.83 (1H, m), 6.76 (2H, d, J 8.6), 7.09 (2H, d, J 8.5), 7.29 (2H, d, J 8.1), 7.51 (2H, d, J 8.2).

Provenance & Evidence