AbstractsChemistry

2-Carboxy-3(3-cyclohexen-1-yl)propionic acid, 3-(3-cyclohexen-1-yl)propionic acid and 3-(3-cyclohexen-1-yl)propionyl chloride were prepared in sequence from ethyl-2-carbethoxy-3-(3-cyclohexen-1-yl)propionate. Cyclization of 3-(3-cyclohexen-1-yl)propionic acid in polyphosphoric acid resulted in the formation of 4, 5, 6, 7-tetrahydroindanone which was identified by its ultraviolet spectrum and its physical properties. 7-Bicyclo[3.3.1] nonen-2-one was prepared by a Friedel-Crafts cyclization of 3-(3-cyclohexen-1-yl)-propionyl chloride. It was identified by its infrared spectrum and its physical properties. 3, 3-Dimethyl-7-bicyclo[3.3.1] nonen-2-one was prepared by methylation of 7-bicyclo[3.3.1] nonen-2-one with potassium triphenylmethide and methyl iodide. It was characterized by its infrared spectrum, nuclear magnetic resonance spectrum and its carbon-hydrogen analysis. The rate of deuterium exchange of 3, 3-dimethyl-7-bicyclo-[3.3.1] nonen-2-one, studied at two base concentrations, was found to be much slower (k = 6.6 X 10⁻³ liters/mole-hour) than that reported for the corresponding saturated ketone (k = 0.36 liter/mole-hour). The slower exchange rate of the unsaturated ketone was ascribed to the strain caused by its carbon-carbon double bond.