3,4-dihydro-2H-pyran → HCID 70506263, compound

HRID 1263087Notes

Reaction equation

HRID 1263087 reaction equation
[OH:1][CH2:2][CH2:3]/[CH:4]=[CH:5]\[CH2:6][C:7]([O:9][CH3:10])=[O:8].[O:11]1[CH:16]=[CH:15][CH2:14][CH2:13][CH2:12]1>C(Cl)Cl.CCOCC.C1(C)C=CC(S([O-])(=O)=O)=CC=1.[NH+]1C=CC=CC=1>[O:11]1[CH2:16][CH2:15][CH2:14][CH2:13][CH:12]1[O:1][CH2:2][CH2:3]/[CH:4]=[CH:5]\[CH2:6][C:7]([O:9][CH3:10])=[O:8]

Participants

6

Reactant 2

HCID 80803,4-dihydro-2H-pyranHCID 15396982HCID 15396982, compound

Product 1

HCID 70506263HCID 70506263, compoundYield 99%

Reagents, catalysts & solvents 3

HCID 466102Benzenesulfonic acid, 4-methyl-, compd. with pyridine (1:1)CatalystHCID 3283Diethyl EtherSolventHCID 6344DichloromethaneSolvent

Procedure

A solution of methyl 6-hydroxy-(Z)-3-hexenoate (0.7684 g, 5.3 mmol), 3,4-dihydropyran (0.72 mL, 7.9 mmol, 1.5 eq) and pyridinium p-toluenesulfonate (PPTS, 125 mg, 0.5 mmol) in methylene chloride (25 mL) is stirred for 4 hours at room temperature. The solution is then diluted with ether (150 mL), and the ether layer is washed with half-saturated brine (50 mL) to remove the catalyst, and dried over magnesium sulfate. Purification by flash chromatography using hexane/ethyl acetate (90:10, v/v) affords methyl 6-tetrahydropyranyloxy-(Z)-3-hexenoate (1.19 g, 99%) as a clear colorless oil: Rf=0.38, hexane/ethyl acetate (7:3, v/v), IR (film) ν2850-3000 (C=CH, alkane CH), 1740 (C=O) and H NMR (CDCl3) δ1.45-1.65 (m, 6H), 2.35 (m, 2H), 3.10 (d, J=6 Hz, 2H), 3.30-3.70 (m, 4H), 3.58 (sS, 3H), 4.55 (br s, 1H), 5.65 (br t, J=6 Hz, 2H).

Workup

  1. washthe ether layer is washed with half-saturated brine (50 mL)
  2. customto remove the catalyst
  3. dry with materialdried over magnesium sulfate
  4. customPurification by flash chromatography

Sources & evidence

ORD record
ord-d81ee63c8f4842f18c866e5ec0dc8415
Source dataset
uspto-grants-1984_06
Patent number
US04455441

Reaction notes

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