反应详情

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.

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