3,4-dihydro-2H-pyran → 2-(7-Bromo-2,2-dimethylheptyloxy)-tetrahydropyran

HRID 2057180Notes

Reaction equation

HRID 2057180 reaction equation
[Br:1][CH2:2][CH2:3][CH2:4][CH2:5][CH2:6][C:7]([CH3:11])([CH3:10])[CH2:8][OH:9].[O:12]1[CH:17]=[CH:16][CH2:15][CH2:14][CH2:13]1>ClCCl.C1(C)C=CC(S(O)(=O)=O)=CC=1>[Br:1][CH2:2][CH2:3][CH2:4][CH2:5][CH2:6][C:7]([CH3:11])([CH3:10])[CH2:8][O:9][CH:13]1[CH2:14][CH2:15][CH2:16][CH2:17][O:12]1

Participants

5

Reactant 2

HCID 80803,4-dihydro-2H-pyranHCID 113106207-Bromo-2,2-dimethylheptan-1-ol

Product 1

HCID 112090012-(7-Bromo-2,2-dimethylheptyloxy)-tetrahydropyranYield 56.3%

Reagents, catalysts & solvents 2

HCID 6101p-Toluenesulfonic acidCatalystHCID 6344DichloromethaneSolvent

Procedure

To a solution of 7-bromo-2,2-dimethylheptan-1-ol (36.0 g, 133.0 mmol) in dichloromethane (60 mL) was added p-toluenesulfonic acid (0.28 g, 1.3 mmol) and 3,4-dihydro-2H-pyran (18.54 g, 213 mmol) at 5-10° C. under cooling with an ice-water bath. The mixture was stirred and allowed to warm to room temperature overnight. The reaction solution was filtered through neutral alumina (200 g), which was rinsed with dichloromethane (500 mL). Concentration of the solvent gave the crude product as a brown oil, which was subjected to column chromatography on silica gel (240 g) using hexanes:ethyl acetate (50:1) as eluent to yield 2-(7-bromo-2,2-dimethylheptyloxy)-tetrahydropyran as a colorless oil (23.0 g, 48%). 1H NMR (300 MHz, CDCl3/TMS): δ (ppm): 4.54 (t, 1H, J=3.0 Hz), 3.84 (m, 1H), 3.51-3.39 (m, 4H), 2.98 (d, 1H, J=9.3 Hz), 1.89-1.80 (m, 3H), 1.70-1.40 (m, 7H), 1.29-1.22 (m, 4H), 0.89 (s, 6H). 13C NMR (75 MHz, CDCl3/TMS): δ (ppm): 99.3, 76.6, 62.1, 39.3, 34.3, 34.2, 33.0, 30.8, 29.2, 25.7, 24.7, 23.2, 19.6. HRMS (LSIMS, nba): Calcd. for C14H27BrO2: 307.1272, found: 307.1245.

Workup

  1. temperatureunder cooling with an ice-water bath
  2. filtrationThe reaction solution was filtered through neutral alumina (200 g), which
  3. washwas rinsed with dichloromethane (500 mL)
  4. customConcentration of the solvent gave the crude product as a brown oil, which

Sources & evidence

ORD record
ord-707e0648b5324873a4e29d8f098c757b
Source dataset
uspto-grants-2008_02
Patent number
US07335799B2

Reaction notes

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