11. A low-melting solid A was isolated, which combustion analysis showed had composition C9H10O. The substance gave a precipitate when treated with 2,4-dinitrophenylhydrazine solution. Furthermore, when reacted with iodoform reagent, a yellow precipitate of CHI3 was observed. Acidification of the alkaline solution from the iodoform test produced a solid material, B. Reduction of Compound A with LiAlH4 gave Compound C (C9H12O). This material, C, also gave Compound B when treated with iodoform reagent. Vigorous oxidation of A, B, or C with sodium dichromate-sulfuric acid solution gave an acid having a mp = 121-122 degrees C. Your friend needs your assistance in determining the structures for Compounds A, B, and C. Can you identify the three compounds?
12. An organic compound (C9H10O) showed strong absorption in the IR spectrum at 1735/cm and gave a semicarbazone having a melting point of 198 degrees C. it burned with a yellow, sooty flame and also gave a positive iodoform test. The 1H NMR spectrum of the compound provided the following information:
2.11 ppm 3H (singlet)
3.65 ppm 2H (singlet)
7.20 ppm 5H (complex multiplet)
Identify the unknown organic compound.
This solution answers two chemistry questions, identifying three unknown compounds based on information provided such as acidification of alkaline solution, the vigorous oxidation, results of and iodoform test and how they burn.