(-)-Benzyl (R)-glycidyl ether → (2R)-1-(benzyloxy)pent-4-en-2-ol

HRID 68386

Reaction equation

HRID 68386 reaction equation
[CH2:1]([O:8][CH2:9][C@H:10]1[CH2:12][O:11]1)[C:2]1[CH:7]=[CH:6][CH:5]=[CH:4][CH:3]=1.[CH:13]([Mg]Br)=[CH2:14]>O1CCCC1.[Cu]I>[CH2:1]([O:8][CH2:9][C@H:10]([OH:11])[CH2:12][CH:13]=[CH2:14])[C:2]1[CH:7]=[CH:6][CH:5]=[CH:4][CH:3]=1

Participants

5

Reactant 2

HCID 159746(-)-Benzyl (R)-glycidyl etherHCID 178418507HCID 178418507, compound

Product 1

HCID 10375318(2R)-1-(benzyloxy)pent-4-en-2-ol

Reagents, catalysts & solvents 2

HCID 24350Copper(1+) iodide; Copper(I) iodide; Cuprous iodide; Cuprous iodide (CuI)CatalystHCID 8028TetrahydrofuranSolvent

Conditions

Temperature
-78 °C

Procedure

To a solution of (2R)-2-[(benzyloxy)methyl]oxirane (167 g, 1.02 mol) in tetrahydrofuran (2 L) was added copper(I) iodide (11.62 g, 61.02 mmol) at room temperature. The mixture was stirred for 5 minutes, then cooled to −78° C. A solution of vinylmagnesium bromide (1 M in tetrahydrofuran, 1.12 L, 1.12 mol) was added drop-wise over 1 hour while the reaction temperature was maintained below −70° C. Upon completion of the addition, the cooling bath was removed and the reaction mixture was left to stir at room temperature for 1 hour, then quenched by slow addition of aqueous ammonium chloride solution (200 mL). After dilution with additional aqueous ammonium chloride solution (1.5 L) and ethyl acetate (1.5 L), the aqueous layer was extracted with ethyl acetate (1 L) and the combined organic layers were washed with aqueous ammonium chloride solution (1.5 L), dried over magnesium sulfate, filtered, and concentrated in vacuo. Three batches of this reaction were carried out and combined to give the product as an orange oil. Yield: 600 g, 3.1 mmol, quantitative. 1H NMR (400 MHz, CDCl3) δ 7.28-7.40 (m, 5H), 5.78-5.90 (m, 1H), 5.08-5.17 (m, 2H), 4.57 (s, 2H), 3.86-3.94 (m, 1H), 3.53 (dd, J=9.6, 3.3 Hz, 1H), 3.39 (dd, J=9.6, 7.4 Hz, 1H), 2.26-2.34 (m, 3H).

Workup

  1. temperaturewas maintained below −70° C
  2. additionUpon completion of the addition
  3. customthe cooling bath was removed
  4. waitthe reaction mixture was left
  5. stirringto stir at room temperature for 1 hour
  6. customquenched by slow addition of aqueous ammonium chloride solution (200 mL)
  7. extractionAfter dilution with additional aqueous ammonium chloride solution (1.5 L) and ethyl acetate (1.5 L), the aqueous layer was extracted with ethyl acetate (1 L)
  8. washthe combined organic layers were washed with aqueous ammonium chloride solution (1.5 L)
  9. dry with materialdried over magnesium sulfate
  10. filtrationfiltered
  11. concentrationconcentrated in vacuo

Sources & evidence

ORD record
ord-9ba6fcd76f444236838ce3ea43f67402
Source dataset
uspto-grants-2014_09
Patent number
US08822456B2

Linked notes

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