2,6-Dimethylhydroquinone → 5,7-Dimethyl-3,4-dihydrospiro[chromene-2,1'-cyclobutan]-6-ol

HRID 2102982Notes

Reaction equation

HRID 2102982 reaction equation
[CH3:1][C:2]1[CH:8]=[C:7]([OH:9])[CH:6]=[C:5]([CH3:10])[C:3]=1[OH:4].[CH:11]([C:13]1(O)[CH2:16][CH2:15][CH2:14]1)=[CH2:12]>O1CCOCC1.C(OCC)(=O)C>[CH3:10][C:5]1[C:3]([OH:4])=[C:2]([CH3:1])[CH:8]=[C:7]2[C:6]=1[CH2:12][CH2:11][C:13]1([O:9]2)[CH2:16][CH2:15][CH2:14]1

Participants

5

Reactant 2

HCID 695602,6-DimethylhydroquinoneHCID 122509441-Ethenylcyclobutan-1-ol

Product 1

HCID 115502985,7-Dimethyl-3,4-dihydrospiro[chromene-2,1'-cyclobutan]-6-olYield 38.7%

Reagents, catalysts & solvents 2

HCID 8857Ethyl AcetateSolventHCID 312751,4-DioxaneSolvent2×

Procedure

To a solution of 2,6-dimethylhydroquinone (2.36 g) and BF3-ether (4.47 mL) in dioxane (10 mL) was added 1-vinyl-cyclobutanol (1.58 g) in dioxane (5 mL) over 50 min at 110° C. under nitrogen. The reaction was refluxed for one additional hour. The solution was diluted with ethyl acetate and washed with water and brine, dried and evaporated. The residue was chromatographed (silica gel, hexane-ethyl acetate 1% to 5%) gave 1.36 g of 5,7-dimethyl-3,4-dihydrospiro[chromene-2,1′-cyclobutan]-6-ol.

Workup

  1. temperatureThe reaction was refluxed for one additional hour
  2. washwashed with water and brine
  3. customdried
  4. customevaporated
  5. customThe residue was chromatographed (silica gel, hexane-ethyl acetate 1% to 5%)

Sources & evidence

ORD record
ord-8432fab18a064b89bf58f106b343089a
Source dataset
uspto-grants-2009_08
Patent number
US07576094B2

Reaction notes

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