Propargyl alcohol → Tetrahydro-2-(2-propynyloxy)-2H-pyran

HRID 271549Notes

Reaction equation

HRID 271549 reaction equation
[O:1]1[CH:6]=[CH:5][CH2:4][CH2:3][CH2:2]1.[CH2:7]([OH:10])[C:8]#[CH:9].CC1C=CC(S(O)(=O)=O)=CC=1.O.CCN(CC)CC>C(Cl)Cl>[O:1]1[CH2:2][CH2:3][CH2:4][CH2:5][CH:6]1[O:10][CH2:7][C:8]#[CH:9]

Participants

6

Reactant 4

HCID 7859Propargyl alcoholHCID 80803,4-dihydro-2H-pyranHCID 8471TriethylamineHCID 521998p-Toluenesulfonic acid monohydrate

Product 1

HCID 98609Tetrahydro-2-(2-propynyloxy)-2H-pyran

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent

Conditions

Temperature
0 °C

Procedure

At 0° C., 3,4-dihydro-2H-pyran (173 ml, 1.90 mol) is added dropwise over 10 min to a soln. of propargyl alcohol (88.49 g, 1.58 mol) and TsOH.H2O (16.08 g, 84.53 mmol) in CH2Cl2 (880 ml). After stirring for 80 min at 0° C., the mixture is warmed to room temperature, stirred for 3 h, treated with Et3N (12 ml), and evaporated. A vacuum distillation (20 mmHg, 80° C.) gives C (224 g, quant.). Colourless oil. 1H-NMR (400 MHz, CDCl3) δ 1.46-1.70 (m, 4 H), 1.70-1.91 (n, 2 H), 2.41 (t, J=2.2), 3.49-3.58 (m, 1 H), 3.81-3.88 (m, 1 H), 3.49-3.58 (m, 1 H), 4.23 (dd, J=15, 2.2), 4.30 (dd, J=15, 2.2), 4.83 (t, J=3.0).

Workup

  1. temperaturethe mixture is warmed to room temperature
  2. stirringstirred for 3 h
  3. customevaporated
  4. distillationA vacuum distillation (20 mmHg, 80° C.)
  5. customgives C (224 g, quant.)

Sources & evidence

ORD record
ord-99d24f7bb44245cf850abb2a2149c860
Source dataset
uspto-grants-2008_11
Patent number
US07452886B2

Reaction notes

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