Potassium;tri(butan-2-yl)boranuide → HCID 10348167, compound

HRID 357274Notes

Reaction equation

HRID 357274 reaction equation
CCC(C)[BH-](C(C)CC)C(C)CC.[K+].[Si:15]([O:22][CH2:23][CH2:24][CH2:25][C@H:26]([C@@H:28]1[C@:45]2([CH3:46])[C@H:31]([C@H:32]3[C@H:42]([CH2:43][CH2:44]2)[C@:40]2([CH3:41])[C@H:35]([CH2:36][C@@H:37]([O:47][CH:48]4[CH2:53][CH2:52][CH2:51][CH2:50][O:49]4)[CH2:38][CH2:39]2)[CH2:34][C:33]3=[O:54])[CH2:30][CH2:29]1)[CH3:27])([C:18]([CH3:21])([CH3:20])[CH3:19])([CH3:17])[CH3:16]>C1COCC1>[Si:15]([O:22][CH2:23][CH2:24][CH2:25][C@H:26]([C@@H:28]1[C@:45]2([CH3:46])[C@H:31]([C@H:32]3[C@H:42]([CH2:43][CH2:44]2)[C@:40]2([CH3:41])[C@H:35]([CH2:36][C@@H:37]([O:47][CH:48]4[CH2:53][CH2:52][CH2:51][CH2:50][O:49]4)[CH2:38][CH2:39]2)[CH2:34][C@H:33]3[OH:54])[CH2:30][CH2:29]1)[CH3:27])([C:18]([CH3:19])([CH3:20])[CH3:21])([CH3:17])[CH3:16]

Participants

4

Reactant 2

HCID 4304157Potassium;tri(butan-2-yl)boranuide2×HCID 10460748HCID 10460748, compound

Product 1

HCID 10348167HCID 10348167, compoundYield 94%

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent2×

Conditions

Temperature
500 °C

Procedure

K-Selectride® (potassium tri-sec-butylborohydride) (8.9 ml, 1M in THF, 8.9 mmol) was added dropwise via syringe to a solution of ketone 2005 (1.7 g, 3.0 mmol) in dry THF (50 ml) at room temperature under argon. The reaction mixture was heated to 500° C. in an oil bath and stirred for 5 hours. The mixture was allowed to cool to room temperature and then quenched by adding 30% H2O2 dropwise until the evolution of gas ceased. Saturated aqueous NH4Cl solution was added and the aqueous solution was extracted (3×) with Et 20. The combined organic extracts were washed with aqueous saturated NaHCO3 solution (2×), distilled H2O (2×), and aqueous saturated NaCl solution, dried over anhydrous MgSO4, filtered, and the solvent was removed in vacuo. The crude product was purified by flash chromatography (SiO2, hexanes:EtOAc 10:1) giving alcohol 2006 as a white solid (1.6 g, 94%). 1H NMR (500 MHz, CDCl) δ 4.73-4.66 (m, 1 H, THP methine H), 3.95-3.85 (m, 1 H, THP CH2), 3.82 (s, 1 H, C-7 H), 3.66-3.52 (m, 3 H, THP CH2C & C-24 H), 3.50-3.45 (m, 1H, C-3 H), 1.08 (s, 3H, C-19 H), 0.91 (d, J=6.6 Hz, C-21 H), 0.89 (s, 9 H, t-Bu), 0.64 (s, 3 H, C-18 H), 0.04 (s, 6 H, TBDMS CH3); MS (CI/isobutane) m/z 577 (M+1, 5%), 493 (M+1-THP, 22%), 475 (M+1-THPOH, 26%), 458 (M+1-THPOH-H2O, 38%), 343 (M+1-THPOH-TBDMSOH, 80%), 325 (M+1-THPOH-TBDMSOH-H2O, 100%); IR (CHCl3) 3430, 2860 cm-1 ; m.p. 130°-133° C.; Anal. calcd. for C35H64 O4Si: C=72.86, H=11.18; Found: C=72.69, H=11.32.

Workup

  1. temperatureto cool to room temperature
  2. customquenched
  3. additionby adding 30% H2O2 dropwise until the evolution of gas
  4. additionSaturated aqueous NH4Cl solution was added
  5. extractionthe aqueous solution was extracted (3×) with Et 20
  6. washThe combined organic extracts were washed with aqueous saturated NaHCO3 solution (2×)
  7. distillationdistilled H2O (2×), and aqueous saturated NaCl solution
  8. dry with materialdried over anhydrous MgSO4
  9. filtrationfiltered
  10. customthe solvent was removed in vacuo
  11. customThe crude product was purified by flash chromatography (SiO2, hexanes:EtOAc 10:1)

Sources & evidence

ORD record
ord-0bd7304d63c347c99ac2bfc9a0cd9acc
Source dataset
uspto-grants-1998_11
Patent number
US05840740

Reaction notes

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