Reaction equation
[CH3:1][O:2][C:3]1[C:4](=[O:10])[CH:5]=[CH:6][C:7](=[O:9])[CH:8]=1.C1(C=CC(O)=CC=1)O.[CH3:19][O:20][CH:21]=[CH:22][C:23]([O:25][Si:26]([CH3:29])([CH3:28])[CH3:27])=[CH2:24]>C1(C)C=CC=CC=1>[CH3:1][O:2][C:3]1[C:4](=[O:10])[CH:5]2[CH:6]([C:7](=[O:9])[CH:8]=1)[CH2:24][C:23]([O:25][Si:26]([CH3:27])([CH3:29])[CH3:28])=[CH:22][CH:21]2[O:20][CH3:19]Participants
Conditions
- Temperature
- 60 °C
Procedure
In a 50 mL round bottom flask, 2-methoxy-1,4-benzoquinone (2.3 g, 16.7 mmol) was suspended in toluene (30 mL). Hydroquinone (95 mg) was added and the resulting suspension was stirred magnetically for 5 min. 1-Methoxy-3-trimethylsilyloxy-1,3-butadiene (Aldrich, used as received, 5.0 g, 4.5 mL, 29.1 mmol) was added in one portion and the reaction was heated under N2 at 60° C. using an oil bath for 18 h. The reaction was removed from the oil bath, allowed to cool to rt and the solvent was removed by evaporation. Crystallization occurred after cooling the mixture to -30° C. for 1 hour. The colorless solid was collected by filtration and washed with hexane (30 mL) giving 4a,5,8,8a-tetrahydro-2,8-dimethoxy-6-trimethylsilyloxynapthalene-1,4-dione ##STR137## as a colorless powder (3.6 g, 11.6 mmol, 70%, >95% pure by 1H NMR, mp 108°-110° C.; 1H NMR (CDCl3) δ0.52 (s, 9H), 2.2-2.4 (m, 2H), 3.18 (s, 3H), 3.47 (t, 1H), 3.80 (s, 3H), 3.92 (m, 2H), 5.20 (d, 1H), 6.12 (s, 1H).
Workup
- customfor 18 h
- customThe reaction was removed from the oil bath
- temperatureto cool to rt
- customthe solvent was removed by evaporation
- customCrystallization
- temperatureafter cooling the mixture to -30° C. for 1 hour
- filtrationThe colorless solid was collected by filtration
- washwashed with hexane (30 mL)
Sources & evidence
- ORD record
- ord-7a32baf5814e4b44b6d1f0e7eb3185b1
- Source dataset
- uspto-grants-1998_01
- Patent number
- US05708168
Linked notes
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