Organic Syntheses, CV 5, 91
Submitted by P. G. Gassman and J. L. Marshall
1.
Checked by William G. Dauben and James L. Chitwood.
1. Procedure
Into a
250-ml. Erlenmeyer flask are placed
45.9 g. (0.298 mole) of 7,7-dimethoxybicyclo[2.2.1]heptene (Note
1),
75 ml. of 5% aqueous sulfuric acid, and a
Teflon-coated magnetic stirring bar. The flask is stoppered, and the mixture is stirred vigorously with a magnetic stirrer for 20 hours. The mixture is extracted with three
40-ml. portions of pentane, and the combined extracts are dried over anhydrous
magnesium sulfate. The drying agent is removed by filtration, and the solvent is distilled through a
12-in. Vigreux column. Fractional distillation of the residual oil yields
28.9 g. (
90%) of colorless
bicyclo[2.2.1]hepten-7-one, b.p.
96–100° (115 mm.),
n25D 1.4786 (Note
2) and (Note
3).
2. Notes
2. The checkers, working at half-scale, obtained an
85% yield of product, b.p.
93–97° (118 mm.).
3. This material is extremely volatile and should be handled with care.
3. Discussion
4. Merits of the Preparation
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