反应详情

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.

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%)