Textbook Question
Two widely used pain relievers are aspirin and acetaminophen. Show how you would synthesize these drugs from phenol.
1
views
Ch. 21 - Carboxylic Acid Derivatives
Wade9th EditionOrganic ChemistryISBN: 9780135213728
Not the one you use?Change textbookSelect a different textbook
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 21, Problem 52
An ether extraction of nutmeg gives large quantities of trimyristin, a waxy crystalline solid of melting point 57°C. The IR spectrum of trimyristin shows a very strong absorption at 1733 cm-1. Basic hydrolysis of trimyristin gives 1 equivalent of glycerol and 3 equivalents of myristic acid (tetradecanoic acid).
(a) Draw the structure of trimyristin.
(b) Predict the products formed when trimyristin is treated with lithium aluminum hydride, followed by aqueous hydrolysis of the aluminum salts.
Verified step by step guidance1
Step 1: Understand the structure of trimyristin. Trimyristin is a triglyceride, meaning it consists of a glycerol backbone esterified with three myristic acid (tetradecanoic acid) molecules. To draw its structure, start with a glycerol molecule (a three-carbon chain with hydroxyl groups on each carbon) and replace each hydroxyl group with an ester group formed by myristic acid (CH₃(CH₂)₁₂COOH).
Step 2: Analyze the IR spectrum data. The strong absorption at 1733 cm⁻¹ indicates the presence of a carbonyl group (C=O), which is characteristic of ester functional groups in trimyristin. This confirms the ester linkage between glycerol and myristic acid.
Step 3: Predict the products of lithium aluminum hydride (LiAlH₄) reduction. LiAlH₄ is a strong reducing agent that reduces esters to alcohols. When trimyristin is treated with LiAlH₄, the ester bonds are cleaved, converting the three myristic acid esters into three molecules of myristyl alcohol (CH₃(CH₂)₁₂CH₂OH) and regenerating the glycerol backbone.
Step 4: Consider the aqueous hydrolysis step. After reduction, the aluminum salts formed during the reaction are hydrolyzed with water, leaving behind the alcohol products (glycerol and myristyl alcohol) in their pure forms.
Step 5: Summarize the reaction products. The final products of the reaction sequence are glycerol (unchanged from the reduction step) and three equivalents of myristyl alcohol, which are derived from the reduction of the ester groups in trimyristin.
Verified video answer for a similar problem:
This video solution was recommended by our tutors as helpful for the problem above.
Video duration:
4mWas this helpful?
Key Concepts
Here are the essential concepts you must grasp in order to answer the question correctly.
Structure of Trimyristin
Trimyristin is a triglyceride composed of glycerol and three myristic acid (tetradecanoic acid) molecules. Understanding its structure involves recognizing the ester linkages formed between the glycerol backbone and the fatty acid chains. The molecular formula is C45H86O6, and its structure can be represented as a glycerol molecule with three myristate groups attached, which is crucial for predicting its reactivity in chemical reactions.
Recommended video:
Guided course
03:04
Drawing Resonance Structures
Infrared (IR) Spectroscopy
IR spectroscopy is a technique used to identify functional groups in organic compounds based on their characteristic absorption of infrared light. The strong absorption at 1733 cm-1 in the IR spectrum of trimyristin indicates the presence of a carbonyl (C=O) group, typical of esters. This knowledge is essential for understanding the molecular structure and confirming the presence of ester linkages in trimyristin.
Recommended video:
Guided course
16:04General Features of IR Spect
Lithium Aluminum Hydride Reduction
Lithium aluminum hydride (LiAlH4) is a powerful reducing agent commonly used to reduce esters and other carbonyl-containing compounds to their corresponding alcohols. In the case of trimyristin, treatment with LiAlH4 will reduce the ester groups to alcohols, yielding glycerol and myristyl alcohol upon hydrolysis. Understanding this reduction process is key to predicting the products formed after the reaction.
Recommended video:
Guided course
07:19Monosaccharides - Reduction (Alditols)
Related Practice
Textbook Question
Phosgene is the acid chloride of carbonic acid. Although phosgene was used as a war gas in World War I, it is now used as a reagent for the synthesis of many useful products. Phosgene reacts like other acid chlorides, but it can react twice.
(b) Predict the products formed when phosgene reacts with 1 equivalent of methanol, followed by 1 equivalent of aniline.
2
views
Textbook Question
Show how you would accomplish the following syntheses. Some of these conversions may require more than one step.
(a) isopentyl alcohol → isopentyl acetate (banana oil)
1
views
Textbook Question
Show how you would accomplish the following syntheses. Some of these conversions may require more than one step.
(b) 3-ethylpentanoic acid → 3-ethylpentanenitrile
1
views
Textbook Question
Phosgene is the acid chloride of carbonic acid. Although phosgene was used as a war gas in World War I, it is now used as a reagent for the synthesis of many useful products. Phosgene reacts like other acid chlorides, but it can react twice.
(a) Predict the products formed when phosgene reacts with excess propan-2-ol.
2
views
Textbook Question
Predict the products of the following reactions.
(l)
1
views