[H-].[Li+].[CH3:3][C:4]([C:11]1[CH2:16][CH2:15][C:14]([CH3:17])=[CH:13][CH:12]=1)([CH3:10])[CH2:5][CH2:6]C(O)=O.[CH:18]([Li])=C.C1COCC1.[CH2:26]([CH2:29][O:30]C)OC>>[CH3:18][C:14]12[CH2:13][CH2:12][C:11]3([CH:16]=[CH:15]1)[CH:26]([C:29](=[O:30])[CH2:6][CH2:5][C:4]3([CH3:3])[CH3:10])[CH2:17]2A mixture of freshly distilled dimethoxyethane (250 ml), lithium hydride (880 mg, 110 mmol) and 4-methyl-4(4-methyl-1,3-cyclohexadien-1-yl)pentanoic acid was refluxed under Argon for 2.5 hours. The mixture was then cooled to 5° C and vinyl lithium in THF (111 g, 130 ml, 208 mmol) was added over a ten minute period. After stirring for an additional 5 minutes, the mixture was quenched by siphoning into a vigorously stirring solution of 28 ml of conc. HCl in 400 ml ice water. The aqueous layer was saturated with sodium chloride, and extracted with methylene chloride. The methylene chloride solution was washed (5% NaOH, 10% NaCl) and then concentrated. The product was crystallized from hexane to yield 7.5 g (40%) of the 1,7,7-trimethyltricyclo[6.2.2.03,8 ]dodec-9-en-4-one (8). Analysis by gas liquid chromatography and thin layer chromatography showed this to be a mixture of two isomers.
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