Concept explainers
The 1H NMR data for the two anomers included very comparable peaks in the δ 2.0–5.6 region but differed in that, as their highest δ peaks, anomer V had a doublet at δ 5.8 (1H, J=12 Hz) while anomer VI had a doublet at δ6.3(1H, J=4 Hz).
(a) Which proton in these anomers would be expected to have these highest δ values?
(b) Why do the signals for these protons appear as doublets?
(c) The relationship between the magnitude of the observed coupling constant and the dihedral angle (when measured using a Newman projection) between C−-H bonds on the adjacent carbons of a C−-C bond is given by the Karplus equation. It indicates that an axial–axial relationship results in a coupling constant of about 9 Hz (observed range is 8–14 Hz) and an equatorial–axial relationship results in a coupling constant of about 2 Hz (observed range is 1–7 Hz). Which of V and VI is the αa anomer and which is the β anomer?
(d) Draw the most stable conformer for each of V and VI.
Want to see the full answer?
Check out a sample textbook solutionChapter 22 Solutions
Organic Chemistry
Additional Science Textbook Solutions
College Physics: A Strategic Approach (3rd Edition)
Chemistry: Structure and Properties (2nd Edition)
Introductory Chemistry (6th Edition)
Anatomy & Physiology (6th Edition)
Campbell Biology in Focus (2nd Edition)
Chemistry: An Introduction to General, Organic, and Biological Chemistry (13th Edition)
- Follow the curved arrows to draw a second resonance structure for each species. Explain and steps for individual understanding.arrow_forwardDraw all reasonable resonance structures for the following cation. Then draw the resonance hybrid. Provide steps and explanationarrow_forwardHow are the molecules or ions in each pair related? Classify them as resonance structures, isomers, or neither.arrow_forward
- How do I solve this Alkyne synthesis homework problem for my Organic Chemistry II class? I have to provide both the intermediate products and the reagents used.arrow_forwardSubstance X is known to exist at 1 atm in the solid, liquid, or vapor phase, depending on the temperature. Additionally, the values of these other properties of X have been determined: melting point enthalpy of fusion 90. °C 8.00 kJ/mol boiling point 130. °C enthalpy of vaporization 44.00 kJ/mol density 2.80 g/cm³ (solid) 36. J.K mol (solid) 2.50 g/mL (liquid) heat capacity 32. J.Kmol (liquid) 48. J.Kmol (vapor) You may also assume X behaves as an ideal gas in the vapor phase. Ex Suppose a small sample of X at 50 °C is put into an evacuated flask and heated at a constant rate until 15.0 kJ/mol of heat has been added to the sample. Graph the temperature of the sample that would be observed during this experiment. o0o 150- 140 130- 120- 110- 100- G Ar ?arrow_forwardMechanism. Provide the mechanism for the reaction below. You must include all arrows, intermediates, and formal charges. If drawing a Sigma complex, draw all major resonance forms. The ChemDraw template of this document is available on Carmen. Br FeBr3 Brarrow_forward
- Organic ChemistryChemistryISBN:9781305580350Author:William H. Brown, Brent L. Iverson, Eric Anslyn, Christopher S. FootePublisher:Cengage LearningMacroscale and Microscale Organic ExperimentsChemistryISBN:9781305577190Author:Kenneth L. Williamson, Katherine M. MastersPublisher:Brooks Cole