Isopropanol → (4-Methyl-3,6-dihydro-2H-pyran-2,2-diyl)dimethanol

HRID 2254036Notes

Reaction equation

HRID 2254036 reaction equation
[H-].[Al+3].[Li+].[H-].[H-].[H-].[CH3:7][C:8]1[CH2:9][C:10]([C:19](OCC)=[O:20])([C:14](OCC)=[O:15])[O:11][CH2:12][CH:13]=1.C(OCC)(=O)C.C(O)(C)C>O1CCCC1.O>[CH3:7][C:8]1[CH2:9][C:10]([CH2:19][OH:20])([CH2:14][OH:15])[O:11][CH2:12][CH:13]=1

Participants

7

Reactant 4

HCID 3776IsopropanolHCID 8857Ethyl AcetateHCID 565258HCID 565258, compoundHCID 21226445Aluminium lithium hydride

Product 1

HCID 21679893(4-Methyl-3,6-dihydro-2H-pyran-2,2-diyl)dimethanol

Reagents, catalysts & solvents 2

HCID 962WaterSolventHCID 8028TetrahydrofuranSolvent2×

Procedure

To 200 ml tetrahydrofuran at 0° C. was added 4.0 g (0.015 mol) lithium aluminum hydride portionwise. A solution of 12.5 g (0.052 mol) of (±)-diethyl 3,6-dihydro-4-methyl-2H-pyran-2,2-dicarboxylate in 60 ml tetrahydrofuran was added dropwise over 30 minutes. The reaction mixture was warmed to ambient temperature. After 2 hours, the reaction was cooled to 0° C. and successively treated with 30 ml ethyl acetate, 30 ml isopropanol, 30 ml water dropwise keeping the temperature under 10° C. The reaction mixture was filtered through celite with acetone, dried over MgSO4, filtered, and concentrated to an oil. Flash chromatography in 1:1 hexanes:ethyl acetate followed by ethyl acetate alone yielded 5.5 g oil.

Workup

  1. temperaturethe reaction was cooled to 0° C.
  2. customunder 10° C
  3. filtrationThe reaction mixture was filtered through celite with acetone
  4. dry with materialdried over MgSO4
  5. filtrationfiltered
  6. concentrationconcentrated to an oil

Sources & evidence

ORD record
ord-91ff4a1d769542da870240624b7afa45
Source dataset
uspto-grants-1993_08
Patent number
US05234900

Reaction notes

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