1,10-Undecadiyne → 2-(Pentadeca-5,14-diynyloxy)tetrahydropyran

HRID 918969Notes

Reaction equation

HRID 918969 reaction equation
[Li]CCCC.[CH:6]#[C:7][CH2:8][CH2:9][CH2:10][CH2:11][CH2:12][CH2:13][CH2:14][C:15]#[CH:16].Br[CH2:18][CH2:19][CH2:20][CH2:21][O:22][CH:23]1[CH2:28][CH2:27][CH2:26][CH2:25][O:24]1>O1CCCC1.CN(P(N(C)C)(N(C)C)=O)C.C1COCC1>[CH2:21]([O:22][CH:23]1[CH2:28][CH2:27][CH2:26][CH2:25][O:24]1)[CH2:20][CH2:19][CH2:18][C:16]#[C:15][CH2:14][CH2:13][CH2:12][CH2:11][CH2:10][CH2:9][CH2:8][C:7]#[CH:6]

Participants

6

Reactant 3

HCID 777641,10-UndecadiyneHCID 5590192-(4-Bromobutoxy)tetrahydro-2H-pyranHCID 178418339Butyllithium

Product 1

HCID 866652612-(Pentadeca-5,14-diynyloxy)tetrahydropyranYield 64%

Reagents, catalysts & solvents 2

HCID 8028TetrahydrofuranSolventHCID 86583969tetrahydrofuran HMPASolvent

Conditions

Temperature
-10 °C

Procedure

n-BuLi (4.86 mL of 2.5 M in hexanes, 12.16 mmol) was added dropwise to a −78° C. solution of undec-1,10-diyne (2.0 g, 13.51 mmol) in dry tetrahydrofuran/HMPA (105 mL, 6:1) under an argon atmosphere. After 30 min, the reaction mixture was warmed to −10° C. over 2 h and maintained at this temperature for 20 min, then re-cooled to −75° C. To this was added a solution of 2-(4-bromobutoxy)-tetrahydropyran (2.4 g, 10.14 mmol) in dry THF (15 mL). The resulting mixture was warmed to room temperature over 3 h, maintained at this temperature for 12 h, then quenched with sat. aq. NH4Cl (25 mL). After 20 min, the mixture was extracted with ether (2×125 mL). The combined ethereal extracts were washed with water (2×100 mL), brine (100 mL), dried over Na2SO4 and concentrated under reduced pressure. The residue was purified by SiO2 column chromatography using 5% EtOAc/hexanes as eluent to give 2-(pentadeca-5,14-diynyloxy)tetrahydropyran (1.97 g, 64%) as a colorless oil. TLC: 10% EtOAc/hexanes, Rf≈0.6; 1H NMR (400 MHz, CDCl3) δ 4.58 (t, J=2.5 Hz, 1H), 3.82-3.89 (m, 1H), 3.71-3.78 (m, 1H), 3.43-3.53 (m, 1H), 3.36-3.47 (m, 1H), 2.01-2.20 (m, 6H), 1.93 (t, J=2.5 Hz, 1H), 1.27-1.81 (m, 20H). Lit. ref: F. Slowinski; C. Aubert; M. Malacria Eur. J. Org. Chem. 2001: 3491.

Workup

  1. temperaturemaintained at this temperature for 20 min
  2. temperaturere-cooled to −75° C
  3. temperatureThe resulting mixture was warmed to room temperature over 3 h
  4. temperaturemaintained at this temperature for 12 h
  5. customquenched with sat. aq. NH4Cl (25 mL)
  6. waitAfter 20 min
  7. extractionthe mixture was extracted with ether (2×125 mL)
  8. washThe combined ethereal extracts were washed with water (2×100 mL), brine (100 mL)
  9. dry with materialdried over Na2SO4
  10. concentrationconcentrated under reduced pressure
  11. customThe residue was purified by SiO2 column chromatography

Sources & evidence

ORD record
ord-09701f7242f443ae86a00b9580317460
Source dataset
uspto-grants-2016_03
Patent number
US09272991B2

Reaction notes

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