1,3-Cyclohexanedicarboxylic acid → 3-Oxabicyclo[3.3.1]nonane-2,4-dione

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

A suspension of 1,3-cyclohexanedicarboxylic acid (490 g, 2.88 mol) in acetic anhydride (1500 ml) was heated to 140° C., refluxing for 2 hours. Acetic anhydride was then removed with distillation (oil bath 180° C). To the residue was added acetic anhydride (1000 ml) and refluxed at 140° C. for 1 hour. The acetic anhydride was removed again with distillation (under house vacuum, about 50° C.). After crystals appeared, the mixture was cooled to room temperature and MTBE (400 ml) was added. The mixture was then cooled to 0-5° C. The crystals were filtered, washed with MTBE (250 ml), and dried under house vacuum to give the title compound (382 g). The filtrate was concentrated to a residue and suspended in MTBE (100 ml) to give the second crop of the title compound (14.0 g). The total yield was 396 g (90.5%). Mp 138-140° C.

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