Chapter 18: Question 18.43 (page 967)
A compound of formula C6H10O2 shows only two absorptions in proton NMR: a singlet at 2.67 ppm and singlet at 2.15 ppm. These absorptions have areas in the ratio 2:3. The IR spectrum shows strong absorption at 1708 cm-1. Propose structure of compound.
Answer:
Over 30 million students worldwide already upgrade their learning with Vaia!
All the tools & learning materials you need for study success - in one app.
Get started for free
Propose mechanisms for
(a) the acid-catalyzed hydration of chloral to form chloral hydrate.
(b) the base-catalyzed hydration of acetone to form acetone hydrate
Question. An unknown compound gives a molecular ion of m/z 70 in the mass spectrum. It reacts with semicarbazide hydrochloride to give a crystalline derivative, but it gives a negative Tollens test. The NMR and IR spectra follow. Propose a structure for this compound, and give peak assignments to account for the absorptions in spectra. Explain why the signal atin the IR spectrum appears at an unusual frequency.
Question: The family of macrolide antibiotics all have large rings (macrocycle) in which an ester is what makes the ring; a cyclic ester is termed as a lactone. One example is amphotericin B, used as an anti-fungal treatment of last resort because of its liver and heart toxicity. Professor Martin Burke of the University of Illnois has been making analogs to retain the antifungal properties but without the toxicity, including this structure published in 2015. (Nature Chemical Biology, (2015) doi: 10.1038/nchembio.1821). The carboxylate of amphotericin B has been replaced with the urea group (shown in red).
(a) Where is the lactone group that forms the ring?
(b) Two groups are circled. What type of functional group are they? Explain.
Show how you would accomplish the following synthetic conversions. You may use any additional reagents and solvents you need.
Name the following ketones and aldehydes. When possible, give both a common name and an IUPAC name.
What do you think about this solution?
We value your feedback to improve our textbook solutions.
