Organic Chemistry (8th Edition)
8th Edition
ISBN: 9780134042282
Author: Paula Yurkanis Bruice
Publisher: PEARSON
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Chapter 25.9, Problem 25P
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?
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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
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b. (1 point) Which Grignard reagent (A, B, C, or D) will lead to the product with the fewest ¹3C NMR signals?
Provide the correct product for the following series of transformation. Hint: The product has a H NMR spectrum with only 2 resonances with relative H integrations of 3:1.
1. Br2
2. 3 eq. NaNH2, NH3
3. CH3I
?
Br.
Br
H3C
CH3
A)
CH3
C)
CH3
B)
D)
=CH3
A
B
D
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.
Chapter 25 Solutions
Organic Chemistry (8th Edition)
Ch. 25.1 - Prob. 1PCh. 25.3 - Which has a higher melting point, glyceryl...Ch. 25.3 - Draw the structure of an optically inactive fat...Ch. 25.3 - Draw the structure of an optically active fat...Ch. 25.5 - Do the identities of R1 and R2 in phosphatidic...Ch. 25.5 - Membranes contain proteins, Integral membrane...Ch. 25.5 - Prob. 8PCh. 25.5 - The membrane phospholipids in deer have a higher...Ch. 25.6 - Treating PGC2 with a strong base such as sodium...Ch. 25.7 - Mark off the isoprene units in menthol, -selinene,...
Ch. 25.7 - Prob. 13PCh. 25.7 - Prob. 14PCh. 25.8 - Propose mechanisms for the Claisen condensation...Ch. 25.8 - Prob. 16PCh. 25.8 - Propose a mechanism for the conversion of...Ch. 25.8 - Propose a mechanism for the biosynthesis of...Ch. 25.8 - Propose a mechanism for the conversion of the E...Ch. 25.8 - The fluoro-substitued geranyl pyrophosphate shown...Ch. 25.8 - Prob. 22PCh. 25.8 - Prob. 23PCh. 25.9 - Draw the individual 1,2-hydride and 1,2-methyl...Ch. 25.10 - Prob. 26PCh. 25.10 - Prob. 27PCh. 25.10 - The acid component of a cholesterol ester is a...Ch. 25.10 - Prob. 29PCh. 25.10 - Prob. 30PCh. 25 - Prob. 31PCh. 25 - An optically active fat, when completely...Ch. 25 - Prob. 33PCh. 25 - a. How many different triacylglycerols are there...Ch. 25 - Cardiolipins are found in heart muscles. Draw the...Ch. 25 - Nutmeg contains a simple, fully saturated...Ch. 25 - Draw the product that is obtained from the...Ch. 25 - Prob. 39PCh. 25 - Prob. 40PCh. 25 - Propose a mechanism for the biosynthesis of...Ch. 25 - 5-Androstene-3.17-dione is isomerized to...Ch. 25 - Prob. 44PCh. 25 - Eudesmol is a sesquiterpene found in eucalyptus....Ch. 25 - Prob. 46PCh. 25 - Prob. 47PCh. 25 - Diethylstilbestrol (DES) was given to pregnant...
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