Organic Chemistry
9th Edition
ISBN: 9781305080485
Author: John E. McMurry
Publisher: Cengage Learning
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Chapter 15.SE, Problem 43AP
Interpretation Introduction
Interpretation:
Why oxazole ring in Bextra is
Concept introduction:
A compound to become aromatic should obey Huckel’s rule. According to Huckel’s rule, any specie that is cyclic, planar and has (4n+2) delocalized Ï€ electrons will be aromatic and stable. Thus species with 2, 6, 10, 14 etc. Ï€ electrons will be aromatic and stable.
To explain:
Why oxazole ring in Bextra is aromatic.
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Stanozolol is an anabolic steroid that promotes muscle growth. Although stanozolol has been used by athletes and body builders, many physical and psychological problems result from prolonged use and it is banned in competitive sports.
a. Explain why the nitrogen heterocycle—a pyrazole ring—is aromatic.
b. In what type of orbital is the lone pair on each N atom contained?
c. Draw all reasonable resonance structures for stanozolol.
d. Explain why the pKa of the N – H bond in the pyrazole ring is comparable to the pKa of the O–H bond, making it considerably more acidic than amines such as CH3NH2 (pKa = 40).
Stanozolol is an anabolic steroid that promotes muscle growth. Although stanozolol has been used by athletes and body builders, many physical and psychological problems result from prolonged use and it is banned in competitive sports.
a.Explain why the nitrogen heterocycle—a pyrazole ring—is aromatic.
b.In what type of orbital is the lone pair on each N atom contained?
c. Draw all reasonable resonance structures for stanozolol.
d.Explain why the pKa of the N—H bond in the pyrazole ring is comparable to the pKa of the O—H bond, making it considerably more acidic than amines such as CH3NH2 (pKa = 40).
Compound A exhibits a peak in its 1H NMR spectrum at 7.6 ppm, indicating that it is aromatic. (a) How are the carbon atoms of the triple bonds hybridized? (b) In what type of orbitals are the π electrons of the triple bonds contained? (c) How many π electrons are delocalized around the ring in A?
Chapter 15 Solutions
Organic Chemistry
Ch. 15.1 - Prob. 1PCh. 15.1 - Give IUPAC names for the following compounds:Ch. 15.1 - Prob. 3PCh. 15.2 - Pyridine is a flat, hexagonal molecule with bond...Ch. 15.3 - Prob. 5PCh. 15.4 - Draw the five resonance structures of the...Ch. 15.4 - Prob. 7PCh. 15.4 - Prob. 8PCh. 15.5 - Prob. 9PCh. 15.5 - Prob. 10P
Ch. 15.6 - Prob. 11PCh. 15.6 - How many electrons does each of the four nitrogen...Ch. 15.SE - Give IUPAC names for the following substances (red...Ch. 15.SE - All-cis cyclodecapentaene is a stable molecule...Ch. 15.SE - 1, 6-Methanonaphthalene has an interesting 1H NMR...Ch. 15.SE - Prob. 16VCCh. 15.SE - Azulene, an isomer of naphthalene, has a...Ch. 15.SE - Give IUPAC names for the following compounds:Ch. 15.SE - Draw structures corresponding to the following...Ch. 15.SE - Prob. 20APCh. 15.SE - Prob. 21APCh. 15.SE - Draw and name all possible aromatic compounds with...Ch. 15.SE - Propose structures for aromatic hydrocarbons that...Ch. 15.SE - Look at the three resonance structures of...Ch. 15.SE - Prob. 25APCh. 15.SE - Prob. 26APCh. 15.SE - Look at the five resonance structures for...Ch. 15.SE - Prob. 28APCh. 15.SE - 3-Chlorocyclopropene, on treatment with AgBF4,...Ch. 15.SE - Prob. 30APCh. 15.SE - Prob. 31APCh. 15.SE - Prob. 32APCh. 15.SE - Which would you expect to be most stable,...Ch. 15.SE - How might you convert 1, 3, 5, 7-cyclononatetraene...Ch. 15.SE - Calicene, like azulene (Problem 15-17), has an...Ch. 15.SE - Pentalene is a most elusive molecule that has been...Ch. 15.SE - Prob. 37APCh. 15.SE - Prob. 38APCh. 15.SE - Compound A, C8H10, yields three substitution...Ch. 15.SE - Prob. 40APCh. 15.SE - Propose structures for compounds that fit the...Ch. 15.SE - Prob. 42APCh. 15.SE - Prob. 43APCh. 15.SE - N-Phenylsydnone, so-named because it was first...Ch. 15.SE - Prob. 45APCh. 15.SE - Prob. 46APCh. 15.SE - Prob. 47APCh. 15.SE - Propose a structure for a molecule C14H12 that has...Ch. 15.SE - The proton NMR spectrum for a compound with...Ch. 15.SE - The proton NMR spectrum of a compound with formula...Ch. 15.SE - Aromatic substitution reactions occur by addition...Ch. 15.SE - Prob. 52APCh. 15.SE - Consider the aromatic anions below and their...Ch. 15.SE - After the reaction below, the chemical shift of Ha...Ch. 15.SE - Prob. 55APCh. 15.SE - Azo dyes are the major source of artificial color...
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