Boron trifluoride etherate → 2-allyl-2-phenyltetrahydro-2H-pyran

HRID 71260

Reaction equation

HRID 71260 reaction equation
[C:1]1([C:7]2(O)[CH2:12][CH2:11][CH2:10][CH2:9][O:8]2)[CH:6]=[CH:5][CH:4]=[CH:3][CH:2]=1.[CH2:14]([Si](C)(C)C)[CH:15]=[CH2:16].B(F)(F)F.CCOCC>C(Cl)Cl>[CH2:16]([C:7]1([C:1]2[CH:6]=[CH:5][CH:4]=[CH:3][CH:2]=2)[CH2:12][CH2:11][CH2:10][CH2:9][O:8]1)[CH:15]=[CH2:14]

Participants

5

Reactant 3

HCID 8000Boron trifluoride etherateHCID 69808AllyltrimethylsilaneHCID 145879022-phenyltetrahydro-2H-pyran-2-ol

Product 1

HCID 666850742-allyl-2-phenyltetrahydro-2H-pyranYield 78.9%

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent

Procedure

To a solution of 2-phenyltetrahydro-2H-pyran-2-ol (1.066 g, 5.98 mmol) and allyltrimethylsilane (1.901 mL, 11.96 mmol) in CH2Cl2 (25 mL) at 0° C. was added BF3.OEt2 (0.758 mL, 5.98 mmol) dropwise, and the mixture was stirred at the same temperature for 1 hr. Then the reaction was quenched with saturated NaHCO3 and the product was extracted with EtOAc. The extract was washed with brine, and the combined aqueous layers were back extracted with EtOAc once and combined. The extracts were dried over Na2SO4 and evaporated to give an oily residue. It was purified by Combiflash (80 g silica gel) eluting with 1:9 followed by 4:6 EtOAc-hexane to give 2-allyl-2-phenyltetrahydro-2H-pyran as oil (0.954 g). 1H NMR (400 MHz, CCl3D) δ ppm 7.10-7.45 (5H, m), 5.47-5.65 (1H, m, J=17.19, 10.11, 7.33, 7.33 Hz), 4.84-5.00 (2H, m), 3.64-3.78 (1H, m), 3.41-3.57 (1H, m), 2.35-2.48 (1H, m), 2.20-2.35 (1H, m), 1.55-1.81 (4H, m), 1.35-1.54 (2H, m).

Workup

  1. customThen the reaction was quenched with saturated NaHCO3
  2. extractionthe product was extracted with EtOAc
  3. washThe extract was washed with brine
  4. extractionthe combined aqueous layers were back extracted with EtOAc once
  5. dry with materialThe extracts were dried over Na2SO4
  6. customevaporated
  7. customto give an oily residue
  8. customIt was purified by Combiflash (80 g silica gel)
  9. washeluting with 1:9

Sources & evidence

ORD record
ord-1a426bcc3fa149da9695a60e0eb0bba4
Source dataset
uspto-grants-2014_09
Patent number
US08822510B2

Linked notes

Loading…