Lithium tri-s-butylborohydride → HCID 57987375, compound

HRID 1869739Notes

Reaction equation

HRID 1869739 reaction equation
CCC(C)[BH-](C(C)CC)C(C)CC.[Li+].[CH2:15]([C@@H:18]1[C:23](=[O:24])[CH:22]=[CH:21][N:20]([C:25]2[CH:30]=[CH:29][C:28]([CH:31]([CH3:33])[CH3:32])=[CH:27][CH:26]=2)[C@H:19]1[C:34]1[CH:39]=[CH:38][C:37]([C:40]([F:43])([F:42])[F:41])=[CH:36][CH:35]=1)[CH:16]=[CH2:17]>C1COCC1>[CH2:15]([C@@H:18]1[C:23](=[O:24])[CH2:22][CH2:21][N:20]([C:25]2[CH:30]=[CH:29][C:28]([CH:31]([CH3:33])[CH3:32])=[CH:27][CH:26]=2)[C@H:19]1[C:34]1[CH:39]=[CH:38][C:37]([C:40]([F:43])([F:41])[F:42])=[CH:36][CH:35]=1)[CH:16]=[CH2:17]

Participants

4

Reactant 2

HCID 3611392Lithium tri-s-butylborohydrideHCID 57987532HCID 57987532, compound

Product 1

HCID 57987375HCID 57987375, compoundYield 85%

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent2×

Conditions

Temperature
-78 °C

Procedure

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).

Workup

  1. customwas kept below −70° C
  2. customquenched with saturated aqueous NH4Cl solution
  3. temperatureAfter warming to room temperature the mixture
  4. customwas partitioned between EtOAc/H2O
  5. customThe layers were separated
  6. extractionthe aqueous layer was further extracted with EtOAc (×2)
  7. washThe combined extracts were washed with brine (×1)
  8. dry with materialdried (Na2SO4)
  9. filtrationfiltered
  10. customevaporated
  11. customThe residue was purified by chromatography on silica
  12. washeluting with 5-10% EtOAc/isohexane

Sources & evidence

ORD record
ord-17a9f60fe67a47059cbe9e2694bdf264
Source dataset
uspto-grants-2009_12
Patent number
US07638629B2

Reaction notes

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