Chemical and spectroscopic information concerning three terpenes is provided. Using this together with the isoprene rule, you should be able to draw structural formulas for these compounds. Use the Drawing Window on the left. When you are finished, check your answer by pressing the appropriate Check Structure button. A help screen is available for the drawing window.
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1. Terpene I is an optically active liquid, formula C10 H16 . Hydrogenation ( 2 H2 + Pt ) gives an optically inactive C10 H20 product. The uv-visible spectrum of I shows strong absorbtion at λmax = 265nm. Ozonolysis of I , followed by hydrogen peroxide treatment, yields 2-isopropylsuccinic acid as the only identified product.
2. Terpene II is a pleasant smelling, optically inactive liquid, formula C10 H18 O. Hydrogenation ( 2 H2 + Pt ) of II gives a C10 H22 O product, which on Jones' oxidation yields a C10 H20 O2 carboxylic acid. Ozonolysis of the original terpene, II , followed by hydrogen peroxide treatment produces 4-oxo-pentanoic acid and acetone in equal molar amounts. Other products may be formed, but are not identified. 3. Terpene III is a pleasant smelling, optically active liquid, formula C10 H14 O. The infrared spectrum of III has a strong carbonyl absorption at 1675 cm-1 , and its 1 H nmr spectrum shows two methyl resonance peaks near δ 1.8 ppm and three vinyl hydrogen signals. Hydrogenation ( 2 H2 + Pt ) of III gives a C10 H18 O product, which has a carbonyl band at 1715 cm-1 in the infrared. Ozonolysis of the original terpene, III , followed by hydrogen peroxide treatment produces a keto diacid, CH3 COCH(CH2 CO2 H)2 . Other products may be formed, but are not identified.