Solution Found!
Compounds A, B, C, and D are constitutionally isomeric,
Chapter 18, Problem 18.63(choose chapter or problem)
Compounds A, B, C, and D are constitutionally isomeric, aromatic compounds with molecular formula C8H10. Deduce the structure of compound D using the following clues: The 1 H NMR spectrum of compound A exhibits two upfield signals as well as a multiplet near 7 ppm (with I=5). The 13C NMR spectrum of compound B exhibits four signals. The 13C NMR spectrum of compound C exhibits only three signals.
Questions & Answers
QUESTION:
Compounds A, B, C, and D are constitutionally isomeric, aromatic compounds with molecular formula C8H10. Deduce the structure of compound D using the following clues: The 1 H NMR spectrum of compound A exhibits two upfield signals as well as a multiplet near 7 ppm (with I=5). The 13C NMR spectrum of compound B exhibits four signals. The 13C NMR spectrum of compound C exhibits only three signals.
ANSWER:Step 1 of 5
The molecular formula \(\left(\mathrm{C}_{8} \mathrm{H}_{10}\right)\) indicates a hydrogen deficiency index of 4 . With only eight carbons present, this almost certainly means that benzene is present in the molecule. The benzene would account for all four elements of unsaturation. Subtracting these six carbons from the molecular formula we have been given leaves only two carbons to use as benzene substituents.