3,4-dihydro-2H-pyran → 2-(4-Bromobutoxy)tetrahydro-2H-pyran

HRID 1950739Notes

Reaction equation

HRID 1950739 reaction equation
[O:1]1[CH:6]=[CH:5][CH2:4][CH2:3][CH2:2]1.[Br:7][CH2:8][CH2:9][CH2:10][CH2:11][OH:12]>O.C1(C)C=CC(S(O)(=O)=O)=CC=1.ClCCl>[Br:7][CH2:8][CH2:9][CH2:10][CH2:11][O:12][CH:6]1[CH2:5][CH2:4][CH2:3][CH2:2][O:1]1

Participants

5

Reactant 2

HCID 80803,4-dihydro-2H-pyranHCID 1183884-Bromobutanol

Product 1

HCID 5590192-(4-Bromobutoxy)tetrahydro-2H-pyranYield 92.3%

Reagents, catalysts & solvents 2

HCID 521998p-Toluenesulfonic acid monohydrateCatalystHCID 6344DichloromethaneSolvent

Procedure

3,4-Dihydro-2H-pyran (8.5 mL, 90.96 mmol) was added dropwise to the dichloromethane (20 mL) solution of 22 (10.7 g, 69.93 mmol) and p-toluenesulfonic acid monohydrate (26.5 mg, 0.1372 mmol). The mixture was stirred at room temperature over night. After removing the solvent, the residue was purified by flash chromatography on silica gel with 5:1 hexanes/ethyl acetate as the eluent to yield product 23 as a colorless oil (15.3 g, 92%). 1H NMR (400 MHz, CDCl3): 1.48-1.62 (m, 4H), 1.68-1.85 (m, 4H), 1.94-2.02 (m, 2H), 3.40-3.53 (m, 4H), 3.74-3.88 (m, 2H), 4.57-4.59 (m, 1H).

Workup

  1. customAfter removing the solvent
  2. customthe residue was purified by flash chromatography on silica gel with 5:1 hexanes/ethyl acetate as the eluent

Sources & evidence

ORD record
ord-8d4d7ab0cbd24c009b0201c71ee62763
Source dataset
uspto-grants-2013_03
Patent number
US08404664B2

Reaction notes

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