Organic Chemistry
7th Edition
ISBN: 9780321803221
Author: Paula Y. Bruice
Publisher: Prentice Hall
expand_more
expand_more
format_list_bulleted
Concept explainers
Videos
Textbook Question
Chapter 25.18, Problem 37P
Draw the individual 1,2-hydride and 1,2-methyl shifts responsible for conversion of the protosterol cation to lanosterol. How many hydride shifts are involved? How many methyl shifts?
Expert Solution & Answer
Want to see the full answer?
Check out a sample textbook solution
Students have asked these similar questions
Draw the two intermediates, including resonance structures, for the attack of nitronium ion on pyrrole. Which position is favored? Why?
Show the effect of conjugation on the carbonyl absorption in an IR spectrum ?
2. (9 points total) Each of the following Grignard reagents undergo reaction with CO₂ (solid).
Grignard reagents:
Number of ¹H NMR signals
in the reaction product:
CI
A
MgBr
MeO
B
MgBr
OMe
MgBr
Me
MgCl
a. (8 points) How many ¹H NMR signals do you expect to see in the spectrum of each product? Assume that the
products are pure and that the carboxylic acid peak is present. Please write directly in the boxes.
b. (1 point) Which Grignard reagent (A, B, C, or D) will lead to the product with the fewest ¹3C NMR signals?
Chapter 25 Solutions
Organic Chemistry
Ch. 25.6 - Prob. 2PCh. 25.6 - Prob. 3PCh. 25.6 - Why does the OH group add to the -carbon rather...Ch. 25.6 - Prob. 5PCh. 25.6 - How many molecules of NADH are formed from the...Ch. 25.7 - Prob. 7PCh. 25.7 - Prob. 8PCh. 25.7 - The oxidation of glyceraldehyde-3-phosphate to...Ch. 25.7 - Prob. 10PCh. 25.8 - Prob. 11P
Ch. 25.8 - Prob. 12PCh. 25.8 - Prob. 13PCh. 25.8 - Propose a mechanism for the reduction of...Ch. 25.9 - Prob. 15PCh. 25.9 - Prob. 16PCh. 25.10 - Acid-catalyzed dehydration reactions are normally...Ch. 25.10 - Prob. 18PCh. 25.10 - Prob. 19PCh. 25.10 - Acid-catalyzed dehydration reactions are normally...Ch. 25.10 - Prob. 21PCh. 25.10 - Prob. 22PCh. 25.11 - Prob. 23PCh. 25.12 - a. What is the name of the enzyme that converts...Ch. 25.15 - Prob. 25PCh. 25.16 - Prob. 26PCh. 25.16 - Prob. 27PCh. 25.17 - Propose mechanisms for the Claisen condensation...Ch. 25.17 - Prob. 29PCh. 25.17 - Propose a mechanism for the conversion of...Ch. 25.17 - Propose a mechanism for the biosynthesis of...Ch. 25.17 - Propose a mechanism for the conversion of the E...Ch. 25.17 - The fluoro-substitued geranyl pyrophosphate shown...Ch. 25.17 - Prob. 35PCh. 25.18 - Draw the individual 1,2-hydride and 1,2-methyl...Ch. 25 - Prob. 38PCh. 25 - Prob. 39PCh. 25 - Prob. 40PCh. 25 - Prob. 41PCh. 25 - Prob. 42PCh. 25 - Prob. 43PCh. 25 - Prob. 44PCh. 25 - Prob. 45PCh. 25 - Prob. 46PCh. 25 - Prob. 47PCh. 25 - Prob. 48PCh. 25 - Prob. 49PCh. 25 - Prob. 50PCh. 25 - Prob. 51PCh. 25 - Prob. 52PCh. 25 - Prob. 53PCh. 25 - Prob. 54PCh. 25 - Prob. 55PCh. 25 - Prob. 56PCh. 25 - Prob. 57PCh. 25 - Prob. 58PCh. 25 - Prob. 59PCh. 25 - Prob. 60PCh. 25 - Prob. 61PCh. 25 - Prob. 62PCh. 25 - UDP-galactose-4-epimerase converts UDP-galactose...Ch. 25 - A student is trying to determine the mechanism for...Ch. 25 - What would be the results of the experiment in...Ch. 25 - Prob. 66PCh. 25 - Propose a mechanism for the biosynthesis of...Ch. 25 - Eudesmol is a sesquiterpene found in eucalyptus....
Knowledge Booster
Learn more about
Need a deep-dive on the concept behind this application? Look no further. Learn more about this topic, chemistry and related others by exploring similar questions and additional content below.Similar questions
- Explain why a carbonyl absorption shifts to lower frequency in an α,β-unsaturated carbonyl compound—a compound having a carbonyl group bonded directly to a carbon–carbon double bond. For example, the carbonyl absorption occurs at 1720 cm−1 for cyclohexanone, and at 1685 cm−1 for cyclohex-2-enone.arrow_forwardDraw the three intermediates, including resonance structures, for the attack of nitronium ion on pyridine. Which position(s) is favored? Why?arrow_forward9a) The proton bonded to the carbon adjacent to the carbonyl group in the following compound can be classified into which chemical shift in the ¹H-NMR spectra of aldehydes and ketones? R or H H - 10.0-12.0 ppm R H -2.0-3.0 ppm NO₂ N (1) 9b) Choose the one below that could be resolved into enantiomers. (1) alpha hydrogens = ? ppm NO₂ NO₂ 9c) Which of the following is the major product of the reaction below. `N H -5.0-7.0 ppm (11) (11) -0.0-1.0 ppm HNO3, H₂SO4 H NO₂ (III) NO₂ (1) and (II) (IV) None of the options (IV)arrow_forward
- 4. What is major product of the reaction sequence shown in the box? – 13C NMR: 6 signals. CH3 IBX CH2=PPH3 A) B) H. C) PPH3 D) ОН TH.arrow_forwardIdentify products A and B from the given 1H NMR data.a. Treatment of CH2 = CHCOCH3 with one equivalent of HCl forms compound A. A exhibits the following absorptions in its 1H NMR spectrum: 2.2 (singlet, 3 H), 3.05 (triplet, 2 H), and 3.6 (triplet, 2 H) ppm. What is the structure of A?b. Treatment of acetone [(CH3)2C = O] with dilute aqueous base forms B. Compound B exhibits four singlets in its 1H NMR spectrum at 1.3 (6 H), 2.2 (3 H), 2.5 (2 H), and 3.8 (1 H) ppm. What is the structure of B?arrow_forwardIdentify products A and B from the given 1H NMR data. a.Treatment of CH2=CHCOCH3 with one equivalent of HCl forms compound A. A exhibits the following absorptions in its 1H NMR spectrum: 2.2 (singlet, 3 H), 3.05 (triplet, 2 H), and 3.6 (triplet, 2 H) ppm. What is the structure of A? b.Treatment of acetone [(CH3)2C=O] with dilute aqueous base forms B. Compound B exhibits four singlets in its 1H NMR spectrum at 1.3 (6 H), 2.2 (3 H), 2.5 (2 H), and 3.8 (1 H) ppm. What is the structure of B?arrow_forward
- Which set of underlined hydrogens has its 1H NMR signal at a higher frequency?arrow_forward12,13arrow_forwardIn addition to α cleavage, some aldehydes and ketones undergo the McLafferty rearrangement. In the McLafferty rearrangement, a hydrogen on a carbon three atoms from the C=O is transferred to the carbonyl oxygen and a carbon–carbon bond is broken. This process forms an alkene and the radical cation derived from an enol, which appears as a fragment in the mass spectrum.a.Draw the products formed from the McLafferty rearrangement of 1phenylpentan-1-one, and identify the fragment that results in the given mass spectrum.arrow_forward
- Use the observed 1H NMR data to decide whether C and its dianion are aromatic, antiaromatic, or not aromatic. C shows NMR signals at –4.25 (6 H) and 8.14–8.67 (10 H) ppm. The dianion of C shows NMR signals at –3 (10 H) and 21 (6 H) ppm. Why are the signals shifted upfield (or downfield) to such a large extent?arrow_forwardDraw the two possible intermediates for the attack of the nitronium ion on naphthalene including the important resonance structures. Which position is favored? Why?arrow_forwardPlease see the attached image. Please explain in as much detail as possible.arrow_forward
arrow_back_ios
SEE MORE QUESTIONS
arrow_forward_ios
Recommended textbooks for you
Organic ChemistryChemistryISBN:9781305580350Author:William H. Brown, Brent L. Iverson, Eric Anslyn, Christopher S. FootePublisher:Cengage Learning
Organic Chemistry
Chemistry
ISBN:9781305580350
Author:William H. Brown, Brent L. Iverson, Eric Anslyn, Christopher S. Foote
Publisher:Cengage Learning
NMR Spectroscopy; Author: Professor Dave Explains;https://www.youtube.com/watch?v=SBir5wUS3Bo;License: Standard YouTube License, CC-BY