p-Toluenesulfonic acid → 2-[(7-Bromoheptyl)oxy]tetrahydro-2H-pyran

HRID 1485818Notes

Reaction equation

HRID 1485818 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][CH2:12][CH2:13][CH2:14][OH:15].CC1C=CC(S(O)(=O)=O)=CC=1>C(Cl)Cl>[Br:7][CH2:8][CH2:9][CH2:10][CH2:11][CH2:12][CH2:13][CH2:14][O:15][CH:6]1[CH2:5][CH2:4][CH2:3][CH2:2][O:1]1

Participants

5

Reactant 3

HCID 6101p-Toluenesulfonic acidHCID 80803,4-dihydro-2H-pyranHCID 662841-Heptanol, 7-bromo-

Product 1

HCID 5590082-[(7-Bromoheptyl)oxy]tetrahydro-2H-pyranYield 849.9%

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent2×

Procedure

Dihydropyran (5.20 g, 6.11 mmol) was added to a stirring 0° C. solution of 7-bromoheptane-1-ol (2) (11.0 g, 56.7 mmol) and a catalytic amount of PTSA in CH2Cl2. After stirring at rt for 12 h, the reaction mixture was diluted with CH2Cl2 (200 mL), washed with water (100 mL×2), brine (100 mL×3), dried over anhydrous sodium sulphate, and evaporated. The residue was purified by silica gel column chromatography using a gradient of 10-20% ethyl acetate/hexane as eluent to give 2-(7-bromoheptyloxyl)tetrahydro-2H-pyran (3) (14.50 g, 92%) as a colorless oil. TLC: 10% EtOAc/hexanes, Rf˜0.55; 1H NMR (400 MHz, CDCl3) δ 4.58-4.56 (m, 1H), 3.84-3.88 (m, 1H), 3.68-3.77 (m, 1H), 3.46-3.51 (m, 1H), 3.33-3.43 (m, 3H), 1.80-1.81 (m, 2H), 1.30-1.62 (m, 14H).

Workup

  1. washwashed with water (100 mL×2), brine (100 mL×3)
  2. dry with materialdried over anhydrous sodium sulphate
  3. customevaporated
  4. customThe residue was purified by silica gel column chromatography

Sources & evidence

ORD record
ord-34e1cd74156b404c922a201028a40504
Source dataset
uspto-grants-2016_08
Patent number
US09422318B2

Reaction notes

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