C[O:2][C:3]1[CH:10]=[C:9]([C:11]([CH3:21])([CH3:20])[C:12](O)([CH3:18])[CH2:13][CH2:14][CH2:15][CH2:16][CH3:17])[CH:8]=[C:5]([O:6]C)[CH:4]=1.[K].CI.COC1C=C(C(C)(C)C(C)=CCCCC)C=C(OC)C=1>CCOCC.C(=S)=S>[CH3:21][C:11]([C:9]1[CH:10]=[C:3]([OH:2])[CH:4]=[C:5]([CH:8]=1)[OH:6])([CH3:20])[CH:12]([CH3:18])[CH2:13][CH2:14][CH2:15][CH2:16][CH3:17]To 0.2 mol. of methyl magnesium bromide (2N in tetrahydrofuran-benzene), under nitrogen, is added 55.6 g. of 2-(3,5-dimethoxyphenyl)-2-methyloct-3-one [J. Amer. Chem. Soc. 70:664 (1948); Helv. Chim. Acta 52:116 (1969)] in tetrahydrofuran. After refluxing for 12 hours the mixture is quenched with saturated aqueous ammonium chloride and extracted with ether. The extracts are washed with water, dried (MgSO4) and the solvent is removed to give 5-(2-hydroxy-1,1,2-trimethylheptyl)resorcinol dimethyl ether as an oil. A solution of 5.9 g. of the carbinol in ether is allowed to react over a six hour period with a suspension of 0.8 g. of metallic potassium in 60 ml. of ether. Carbon disulfide (1.5 g.) is added and the mixture is stirred for 30 minutes, then 2.8 g. of methyl iodide is added and the reaction mixture is refluxed for six hours and left at 25° for 12 hours. The mixture is filtered and the filtrate is concentrated and distilled in vacuo. The distillate is dissolved in ethanol, refluxed with Raney nickel and redistilled to give a mixture of 5-(1,1,2-trimethylhept-2-enyl)resorcinol dimethyl ether and 5-(1,1-dimethyl-2-methylenylheptyl)resorcinol dimethyl ether. Removal of the protective groups and hydrogenation is accomplished as described in Example 8 to give 5-(1,1,2-trimethylheptyl)resorcinol.
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