Methyl iodide → 2,4,8-Trimethylspiro[5.5]undeca-1,4,8-trien-3-one

Participants

Reaction Conditions

Reaction Steps

To a 250 mL glass reaction vessel containing an ethyl acetate (70 mLs) solution of N,N-dimethyl,2,6-dimethyl-4-aminomethylphenol (3.58 g; 20 mmols), there was added methyl iodide (20 mmols) to give a colorless slurry. The vessel was sealed and 2-methyl-1,3-butadiene (100 mmols) was introduced into the system. The reaction mixture was heated to 135° C. and the pressure was increased from atmospheric to 75 psig. The reaction mixture was maintained at these conditions for approximately 4 hours. The reaction vessel was then allowed to cool to room temperature. After cooling the black reaction mixture was filtered to remove ammonium iodide salt by-product. The filtrate was concentrated to afford a viscous oil which was purified by column chromatography (silica gel eluted with heptane) to give 1.1 g of 2,4,8-trimethylspiro[5.5]undeca-1,4,8-trien-3-one and 2,4,9-trimethylspiro[5.5]undeca-1,4,8-trien-3-one (33% yield based on N,N-dimethyl,2,6-dimethyl-4-aminomethylphenol starting reactant).

Provenance & Evidence