Textbook Question
Show how you would use Grignard syntheses to prepare the following alcohol from the indicated starting material and any other necessary reagents.
(a) octan-3-ol from hexanal, CH3(CH2)4CHO
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Ch.10 - Structure and Synthesis of Alcohols
Wade9th EditionOrganic ChemistryISBN: 9780135213728
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Table of contents
- Ch.1 - Structure and Bonding107
- Ch. 2 - Acids and Bases; Functional Groups115
- Ch.3 - Structure and Stereochemistry of Alkanes100
- Ch.4 - The Study of Chemical Reactions99
- Ch.5 - Stereochemistry93
- Ch.6 - Alkyl Halides; Nucleophilic Substitution118
- Ch. 7 - Structure and Synthesis of Alkenes; Elimination158
- Ch.8 - Reactions of Alkenes171
- Ch.9 - Alkynes91
- Ch.10 - Structure and Synthesis of Alcohols143
- Ch.11 - Reactions of Alcohols104
- Ch. 12 - Infrared Spectroscopy and Mass Spectrometry22
- Ch. 13 - Nuclear Magnetic Resonance Spectroscopy45
- Ch. 14 - Ethers, Epoxides, and Thioethers72
- Ch. 15 - Conjugated Systems, Orbital Symmetry, and Ultraviolet Spectroscopy89
- Ch. 16 - Aromatic Compounds74
- Ch. 17 - Reactions of Aromatic Compounds126
- Ch. 18 - Ketones and Aldehydes193
- Ch. 19 - Amines129
- Ch. 20 - Carboxylic Acids77
- Ch. 21 - Carboxylic Acid Derivatives141
- Ch. 22 - Condensations and Alpha Substitutions of Carbonyl Compounds175
- Ch. 23 - Carbohydrates and Nucleic Acids93
- Ch. 24 - Amino Acids, Peptides, and Proteins54
Chapter 10, Problem 38b
Show how you would synthesize the following alcohol from appropriate alkene.
(b) 
Verified step by step guidance1
Step 1: Identify the target alcohol structure. The product is a cyclohexane ring with a methyl group and an alcohol group attached to adjacent carbons. The alcohol group is on a wedge (indicating stereochemistry), and the methyl group is also on a wedge.
Step 2: Determine the appropriate alkene precursor. To synthesize this alcohol, the precursor should be a cyclohexene with a methyl group attached to one of the double-bonded carbons. This ensures regioselectivity during the addition reaction.
Step 3: Choose the reaction conditions for hydroxylation. To add the hydroxyl group with stereochemistry, use hydroboration-oxidation. This involves two steps: (a) reaction with BH₃ or a borane derivative to add the boron atom anti-Markovnikov and syn to the methyl group, and (b) oxidation with H₂O₂/NaOH to replace the boron atom with an OH group.
Step 4: Ensure stereochemical control. Hydroboration-oxidation proceeds with syn addition, meaning the OH group and the methyl group will be added to the same face of the cyclohexane ring, matching the stereochemistry of the target alcohol.
Step 5: Verify the product. After the reaction, confirm that the alcohol group and methyl group are on adjacent carbons and both are on the same face of the ring (wedge orientation). This matches the target structure.
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Key Concepts
Here are the essential concepts you must grasp in order to answer the question correctly.
Alkene Reactivity
Alkenes are unsaturated hydrocarbons characterized by at least one carbon-carbon double bond. Their reactivity is primarily due to this double bond, which can undergo various reactions such as electrophilic addition. Understanding the types of reactions that alkenes can participate in is crucial for synthesizing alcohols from them.
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Alkene Metathesis Concept 1
Hydroboration-Oxidation
Hydroboration-oxidation is a two-step reaction process used to convert alkenes into alcohols. In the first step, an alkene reacts with borane (BH3) to form an organoborane intermediate, which is then oxidized in the second step using hydrogen peroxide (H2O2) and a base. This method provides a syn addition of water across the double bond, leading to the formation of alcohols with anti-Markovnikov selectivity.
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Markovnikov's Rule
Markovnikov's Rule states that in the addition of HX to an alkene, the hydrogen atom will attach to the carbon with the greater number of hydrogen atoms already attached, while the halide (X) will attach to the carbon with fewer hydrogen atoms. This principle is essential for predicting the outcome of reactions involving alkenes and is particularly relevant when determining the structure of the resulting alcohol after synthesis.
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Related Practice
Textbook Question
Show how you would synthesize the following alcohol from appropriate alkene.
(d)
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Textbook Question
Show how you would synthesize the following alcohol from appropriate alkene.
(a)
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Textbook Question
Show how you would use Grignard syntheses to prepare the following alcohol from the indicated starting material and any other necessary reagents.
(d) 2-cyclohexylethanol from bromocyclohexane
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Textbook Question
Write structures for a homologous series of alcohols (R―OH) having from one to six carbons.
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Textbook Question
Starting from bromobenzene and any other reagents and solvents you need, show how you would synthesize the following compounds. Any of these products may be used as starting materials in subsequent parts of this problem.
d. 3-phenylprop-2-en-1-ol
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