Triethylborane → HCID 13476231, compound

HRID 236661Notes

Reaction equation

HRID 236661 reaction equation
O1CCCC1.[F:6][C:7]1[CH:12]=[CH:11][C:10]([C:13]2[CH:18]=[C:17]([CH3:19])[CH:16]=[C:15]([CH3:20])[C:14]=2/[CH:21]=[CH:22]/[CH:23]([OH:32])[CH2:24][C:25](=[O:31])[CH2:26][C:27]([O:29][CH3:30])=[O:28])=[CH:9][C:8]=1[CH3:33].C(B(CC)CC)C.[BH4-].[Na+]>CO>[F:6][C:7]1[CH:12]=[CH:11][C:10]([C:13]2[CH:18]=[C:17]([CH3:19])[CH:16]=[C:15]([CH3:20])[C:14]=2/[CH:21]=[CH:22]/[CH:23]([OH:32])[CH2:24][CH:25]([OH:31])[CH2:26][C:27]([O:29][CH3:30])=[O:28])=[CH:9][C:8]=1[CH3:33]

Participants

6

Reactant 4

HCID 7357TriethylboraneHCID 8028TetrahydrofuranHCID 4311764Sodium borohydrideHCID 13476230HCID 13476230, compound

Product 1

HCID 13476231HCID 13476231, compound

Reagents, catalysts & solvents 1

HCID 887MethanolSolvent

Conditions

Temperature
-78 °C

Procedure

Into a glass vessel under nitrogen was charged tetrahydrofuran (22 ml), methyl E-7-(4'-fluoro-3,3',5-trimethyl[1,1'-biphenyl]-2-yl)-5-hydroxy-3-oxo-6-heptenoate (3.0 g, 7.8 mmole) and triethylborane (0.92 g, 9.4 mmole) at ambient temperature and air was bubbled through the solution. After a 5 minute age, the solution was cooled to -78° C. Sodium borohydride (350 mg, 9.25 mmole) was added followed by the addition over 15 minutes of methanol (5 ml) maintaining a temperature below -65° C. After a 30 minute age at -78° C. the mixture is carefully quenched into a rapidly stirred solution of 30% hydrogen peroxide (15 ml) and water (30 ml) at 20° C., aged 30 min then extracted with 50 ml of ethyl acetate. The organic extract was washed successively with 1N aqueous hydrochloric acid (25 ml), water (25 ml) and pH 7 buffer (25 ml), then dried over sodium sulfate (25 g). After filtration, the solution was concentrated to an oil in vacuo. Crystallization was induced by flushing with hexane, and reconcentrating in vacuo to yield the title compound in 90% assay yield (2.71 g). The product was triturated with hexanes to yield a white solid, mp. 78°-80° C. (dec). HPLC assay indicated a purity of 99%.

Workup

  1. customair was bubbled through the solution
  2. temperaturemaintaining a temperature below -65° C
  3. customAfter a 30 minute age at -78° C. the mixture is carefully quenched into a rapidly stirred solution of 30% hydrogen peroxide (15 ml) and water (30 ml) at 20° C., aged 30 min
  4. extractionthen extracted with 50 ml of ethyl acetate
  5. extractionThe organic extract
  6. washwas washed successively with 1N aqueous hydrochloric acid (25 ml), water (25 ml) and pH 7 buffer (25 ml)
  7. dry with materialdried over sodium sulfate (25 g)
  8. filtrationAfter filtration
  9. concentrationthe solution was concentrated to an oil in vacuo
  10. customCrystallization
  11. customby flushing with hexane

Sources & evidence

ORD record
ord-6e03044b0bf94062a5e7f7b0cd1d04a9
Source dataset
uspto-grants-1987_02
Patent number
US04645854

Reaction notes

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