The 1 H NMR spectra of formic acid (HCO2H), maleic acid (cis-HO2CCH CHCO2H), and malonic

Many carboxylic acids are much better known by their common names than by their systematic names. Some of these follow. Provide a structural formula for each one on the basis of its systematic name. (a) 2-Hydroxypropanoic acid (better known as lactic acid, it is found in sour milk and is formed in the muscles during exercise) (b) 2-Hydroxy-2-phenylethanoic acid (also known as mandelic acid, it is obtained from plums, peaches, and other fruits) (c) Tetradecanoic acid (also known as myristic acid, it can be obtained from a variety of fats) (d) 10-Undecenoic acid (also called undecylenic acid, it is used, in combination with its zinc salt, to treat fungal infections such as athletes foot) Problems 763 car02745_ch18_736-769.indd 763 10/9/12 1:32 PM (e) 3,5-Dihydroxy-3-methylpentanoic acid (also called mevalonic acid, it is an important intermediate in the biosynthesis of terpenes and steroids) (f) (E)-2-Methyl-2-butenoic acid (also known as tiglic acid, it is a constituent of various natural oils) (g) 2-Hydroxybutanedioic acid (also known as malic acid, it is found in apples and other fruits) (h) 2-Hydroxy-1,2,3-propanetricarboxylic acid (better known as citric acid, it contributes to the tart taste of citrus fruits) (i) 2-(p-Isobutylphenyl)propanoic acid (an antiinflammatory drug better known as ibuprofen) (j) o-Hydroxybenzenecarboxylic acid (better known as salicylic acid, it is obtained from willow bark)

Give an acceptable IUPAC name for each of the following: (a) CH3(CH2)6CO2H (f) CH3(CH2)4CH(CO2H)2 (b) CH3(CH2)6CO2K (g) CO2H (c) H2C CH(CH2)5CO2H (d) H3C C HH (CH2)4CO2H C (e) HO2C(CH2)6CO2H (h) CH(CH2)4CO2H

Rank the compounds in each of the following groups in order of decreasing acidity: (a) Acetic acid, ethane, ethanol (b) Benzene, benzoic acid, benzyl alcohol (c) 1,3-Propanediol, propanedioic acid, propanoic acid (d) Acetic acid, ethanol, trifluoroacetic acid, 2,2,2-trifluoroethanol, trifluoromethanesulfonic acid (CF3SO2OH)

Identify the more acidic compound in each of the following pairs: (a) CF3CH2CO2H or CF3CH2CH2CO2H (b) CH3CH2CH2CO2H or CH3C{CCO2H

Propose methods for preparing butanoic acid from each of the following: (a) 1-Butanol (c) 1-Butene (e) 2-Propanol (b) Butanal (d) 1-Propanol (f) CH3CH2CH(CO2H)2

It is sometimes necessary to prepare isotopically labeled samples of organic substances for probing biological transformations and reaction mechanisms. Various sources of the radioactive mass-14 carbon isotope are available. Describe synthetic procedures by which benzoic acid, labeled with 14C at its carbonyl carbon, could be prepared from benzene and the following 14C-labeled precursors. You may use any necessary organic or inorganic reagents. (a) CH3Cl (b) HCH O X (c) CO2

Give the product of the reaction of pentanoic acid with each of the following reagents: (a) Sodium hydroxide (b) Sodium bicarbonate (c) Thionyl chloride (d) Phosphorus tribromide (e) Benzyl alcohol, sulfuric acid (catalytic amount) (f) Lithium aluminum hydride, then hydrolysis (g) Phenylmagnesium bromide

Show how butanoic acid may be converted to each of the following compounds: (a) 1-Butanol (c) 1-Chlorobutane (e) Phenyl propyl ketone (b) Butanal (d) Butanoyl chloride (f) 4-Octanone

Each of the following reactions has been reported in the chemical literature and gives a single product in good yield. What is the product in each reaction?

The compound shown was subjected to the following series of reactions to give a product having the molecular formula C9H9ClO3. What is this product?

Show by a series of equations how you could synthesize each of the following compounds from the indicated starting material and any necessary organic or inorganic reagents: (a) 2-Methylpropanoic acid from tert-butyl alcohol (b) 3-Methylbutanoic acid from tert-butyl alcohol (c) 3,3-Dimethylbutanoic acid from tert-butyl alcohol (d) HO2C(CH2)5CO2H from HO2C(CH2)3CO2H (e) 3-Phenyl-1-butanol from C6H5 CH3CHCH2CN W (f) Cl OH O Cl O OH from (g) 2,4-Dimethylbenzoic acid from m-xylene (h) 4-Chloro-3-nitrobenzoic acid from p-chlorotoluene (i) (Z)-CH3CH CHCO2H from propyne

(a) Which stereoisomer of 4-hydroxycyclohexanecarboxylic acid (cis or trans) can form a lactone? What is the conformation of the cyclohexane ring in the starting hydroxy acid? In the lactone? HO CO2H (b) Repeat part (a) for the case of 3-hydroxycyclohexanecarboxylic acid.

When compound A is heated, two isomeric products are formed. What are these two products? CO2H CO2H Cl Compound A

A certain carboxylic acid (C14H26O2), which can be isolated from whale blubber or sardine oil, yields nonanal and O CH(CH2)3CO2H on ozonolysis. What is the structure of this acid?

When levulinic acid (CH3CCH2CH2CO2H) O X was hydrogenated at high pressure over a nickel catalyst at 220C, a single product, C5H8O2, was isolated in 94% yield. This compound lacks hydroxyl absorption in its IR spectrum. What is a reasonable structure for the compound?

On standing in dilute aqueous acid, compound A is smoothly converted to mevalonolactone. Suggest a reasonable mechanism for this reaction. What other organic product is also formed?

Suggest reaction conditions suitable for the preparation of compound A from 5-hydroxy-2- hexynoic acid. CH3CHCH2C OH CCO2H 5-Hydroxy-2-hexynoic acid O O H3C Compound A

In the presence of the enzyme aconitase, the double bond of aconitic acid undergoes hydration. The reaction is reversible, and the following equilibrium is established: C HO2C H CH2CO2H CO2H C Aconitic acid (4% at equilibrium) Isocitric acid (C6H8O7) (6% at equilibrium) Citric acid (C6H8O7) (90% at equilibrium) H2O H2O (a) The major tricarboxylic acid present is citric acid, the substance responsible for the tart taste of citrus fruits. Citric acid is achiral. What is its structure? (b) What must be the constitution of isocitric acid? (Assume that no rearrangements accompany hydration.) How many stereoisomers are possible for isocitric acid?

The 1 H NMR spectra of formic acid (HCO2H), maleic acid (cis-HO2CCH CHCO2H), and malonic acid (HO2CCH2CO2H) are similar in that each is characterized by two singlets of equal intensity. Match these compounds with the designations A, B, and C on the basis of the appropriate 1 H NMR chemical shift data. Compound A: signals at 3.2 and 12.1 Compound B: signals at 6.3 and 12.4 Compound C: signals at 8.0 and 11.4

Compounds A and B are isomers having the molecular formula C4H8O3. Identify A and B on the basis of their 1 H NMR spectra. Compound A: 1.3 (3H, triplet); 3.6 (2H, quartet); 4.1 (2H, singlet); 11.1 (1H, broad singlet) Compound B: 2.6 (2H, triplet); 3.4 (3H, singlet); 3.7 (2H triplet); 11.3 (1H, broad singlet)

Compounds A and B are carboxylic acids. Identify each one on the basis of its 1 H NMR spectrum. (a) Compound A (C3H5ClO2) (Figure 18.10). (b) Compound B (C9H9NO4) has a nitro group attached to an aromatic ring (Figure 18.11).

The dihydroxy acid shown was prepared as a single enantiomer and underwent spontaneous cyclization to give a -lactone, What are the RS configurations of the chirality centers in this lactone? (No stereochemistry is implied in the structural drawing.) (CH2)10CH3 CH3(CH2)5 O O OH 2 3 5 CH3(CH2)5CHCHCH2CH(CH2)10CH3 HO2C OH OH SR R A. 2R, 3R, 5R C. 2S, 3R, 5R B. 2R, 3R, 5S D. 2S, 3R, 5S

The product of the following reaction has the constitution shown. No stereochemistry is implied. Deduce the stereochemistry on the basis of the fact that iodolactonization is normally an anti addition and it was determined experimentally that the ring junction is cis.

What is the structure of the lactone formed by iodolactonization of 4-pentynoic acid (HC{CCH2CH2CO2H)? Anti addition to the triple bond occurs.

Assume that the following reaction proceeds through a bridged selenonium ion. C6H5SeCl CH2Cl2,78C O OH O O C6H5Se What Lewis structure best represents the bridged selenonium ion?

What is compound X?