Sulfuric Acid → HCID 90431843, compound

Participants

Reaction Conditions

Reaction Steps

Under a nitrogen atmosphere, a diethylzinc solution in toluene (concentration: 15% by weight, 6.92 g, 8.4 mmol) was placed into a 100-ml flask equipped with a stirring apparatus, a dropping funnel, and a thermometer, and cooled to −25° C. Chloroiodomethane (2.96 g, 16.8 mmol) was placed into the dropping funnel, and added dropwise with the temperature kept between −20 and −25° C. After completion of the dropwise addition, the mixture was stirred at −10 to −20° C. for 15 minutes, and then cooled to −25° C. At the same temperature, (E)-2-methyl-4-(3-methylphenyl)pent-2-en-1-ol (0.80 g, 4.2 mmol) was added dropwise over a period of 20 minutes. After completion of the dropwise addition, the stirring was continued at −10 to −25° C. for 20 minutes. Next, a 20% aqueous sulfuric acid solution (3.1 ml) was added. After stirring for 10 minutes, the aqueous layer was separated, and the organic layer was washed twice with water (10 ml). The solvent was recovered under reduced pressure to obtain a condensed residue. This residue was purified by silica gel column chromatography (hexane:ethyl acetate=9:1). [(1R*,2S*)-1-Methyl-2-((R*)-1-(3-methylphenyl)ethyl)cyclopropyl]methanol (0.38 g, 1.9 mmol, 45% yield) was obtained as the main isomer, and [(1R*,2S*)-1-methyl-2-((S*)-1-(3-methylphenyl)ethyl)cyclopropyl]methanol (0.014 g, 0.069 mmol, yield 1.6%) was obtained as a minor isomer. The relative configurations of the main isomer and the minor isomer were determined by NOESY measurement.

Provenance & Evidence