Organic Chemistry 2nd Edition solutions

Organic Chemistry 2
At high temperatures, alkanes can undergo dehydrogenation to produce alkenes. For example: C C H H H H H H C C H H H H Ethane Ethylene H2 Hydrogen gas 750 C + This reaction is used industrially to prepare ethylene while simultaneously serving as a source of hydrogen gas. Explain why dehydrogenation o

Organic Chemistry 2
Predict the major product(s) for each of the following reactions: KMnO4 H2 Pt HCl 2) NaBH4 Br2 H2O 1) Hg(OAc)2 , H2O NaOH, cold

Organic Chemistry 2
Predict the major product(s) for each of the following reactions: H2 Pt HBr Br2 1) MCPBA 2) H3O+ 2) H2O2, NaOH 1) BH3 THF

Organic Chemistry 2
Propose a mechanism for each of the following reactions: OH H3O+ (a) OH H3O+ (b) Br HBr (c) Br HBr (d)

Organic Chemistry 2
Compound A reacts with one equivalent of H2 in the presence of a catalyst to give methylcyclohexane. Compound A can be formed upon treatment of 1-bromo-1-methylcyclohexane with sodium methoxide. What is the structure of compound A?

Organic Chemistry 2
Suggest an efficient synthesis for each of the following transformations: (a) (b)

Organic Chemistry 2
Suggest an efficient synthesis for the following transformation: OH

Organic Chemistry 2
How many different alkenes will produce 2,4-dimethylpentane upon hydrogenation? Draw them.

Organic Chemistry 2
Compound A is an alkene that was treated with ozone (followed by DMS) to yield only (CH3CH2CH2)2CRO. Identify the major product that is expected when compound A is treated with MCPBA followed by aqueous acid (H3O+).

Organic Chemistry 2
Suggest an efficient synthesis for each of the following transformations: OH OH (a) Br Br (b) Cl (c) OH OH OH (d)

Organic Chemistry 2
Suggest an efficient synthesis for each of the following transformations: (a) OH OH (b)

Organic Chemistry 2
Compound A has molecular formula C7H15Br. Treatment of compound A with sodium ethoxide yields only one elimination product (compound B) and no substitution products. When compound B is treated with dilute sulfuric acid, compound C is obtained, which has molecular formula C7H16O. Draw the structures o

Organic Chemistry 2
Suggest suitable reagents to perform each of the following transformations: Br OH Br + En HO + En

Organic Chemistry 2
1 (R)-Limonene is found in many citrus fruits, including oranges and lemons: Draw the structures and identify the relationship of the two products obtained when (R)-limonene is treated with excess hydrogen in the presence of a catalyst.

Organic Chemistry 2
Suggest suitable reagents to perform the following transformation: OH Racemic

Organic Chemistry 2
Propose a mechanism for the following transformation: O MeO OH MeOH [H2SO4]

Organic Chemistry 2
Propose a mechanism for each of the following transformations: OH H3O+ (a) Br HBr (b)

Organic Chemistry 2
Predict the major product(s) for each of the following reactions: ? H2 (PPh3) 3RhCl (a) ? H3O+ (b) 1) BH3 THF 2) H2O2 (c) , NaOH ? 1) MCPBA 2) H3O (d) +

Organic Chemistry 2
Explain why each of the following alcohols cannot be prepared via hydroboration-oxidation: OH (a) OH (b) OH (c)

Organic Chemistry 2
Compound X is treated with Br2 to yield meso-2,3- dibromobutane. What is the structure of compound X?

Organic Chemistry 2
Identify the alkene that would yield the following products via ozonolysis: H H O O + (a) O + H O (b) O + O (c) O H O (d)

Organic Chemistry 2
The following reaction is observed to be regioselective. Draw a mechanism for the reaction and explain the source of regioselectivity in this case: O O Br HBr

Organic Chemistry 2
Identify the reagents you would use to accomplish each of the following transformations: Br Br OH OH Br Cl Cl OH OH O O H OH Br + En OH + En

Organic Chemistry 2
Identify the reagents you would use to accomplish each of the following transformations: O Br OH HO Br HO OH HO Br OH OH + En OH OH + En

Organic Chemistry 2
2 Identify which of the following two reactions you would expect to occur more rapidly: (1) addition of HBr to 2-methyl-2-pentene or (2) addition of HBr to 4-methyl-1-pentene. Explain your choice.

Organic Chemistry 2
Predict the major product(s) of the following reaction: Br2 H2S

Organic Chemistry 2
Suggest an efficient synthesis for the following transformation: Br OH + En

Organic Chemistry 2
Compound X has molecular formula C7H14. Hydrogenation of compound X produces 2,4- dimethylpentane. Hydroboration-oxidation of compound X produces a racemic mixture of 2,4- dimethyl-1-pentanol (shown below). Predict the major product(s) obtained when compound X is treated with aqueous acid (H3O+). 2,4

Organic Chemistry 2
When (R)-2-chloro-3-methylbutane is treated with potassium tert-butoxide, a monosubstituted alkene is obtained. When this alkene is treated with HBr, a mixture of products is obtained. Draw all of the expected products

Organic Chemistry 2
Compound Y has molecular formula C7H12. Hydrogenation of compound Y produces methylcyclohexane. Treatment of compound Y with HBr in the presence of peroxides produces the following compound: Br Predict the products when compound Y undergoes ozonolysis.

Organic Chemistry 2
Muscalure is the sex pheromone of the common housefly and has the molecular formula C23H46. When treated with O3 followed by DMS, the following two compounds are produced. Draw two possible structures for muscalure. H O H O

Organic Chemistry 2
Propose a plausible mechanism for each of the following reactions: O OH [H2SO4] (a) HO O O HO Conc. H2SO4 (b

Organic Chemistry 2
Suggest an efficient synthesis for the following transformation: Cl H H O O

Organic Chemistry 2
Propose a plausible mechanism for the following reaction: OH O Br Br2

Organic Chemistry 2
Propose a plausible mechanism for the following process, called iodolactonization: OH O O O I I2

Organic Chemistry 2
When 3-bromocyclopentene is treated with HBr, the observed product is a racemic mixture of trans- 1,2-dibromocyclopentane. None of the corresponding cis-dibromide is observed. Propose a mechanism that accounts for the observed stereochemical outcome: Br Br Br En Br Br Not observed + HBr

Organic Chemistry 2
Taxol (compound 3) can be isolated from the bark of the Pacific yew tree, Taxus brevifolia, and is currently used in the treatment of several kinds of cancer, including breast cancer. Each yew tree contains a very small quantity of the precious compound (approximately 300 mg), enough for just one dos

Organic Chemistry 2
When adamantylideneadamantane, shown below, is treated with bromine, the corresponding bromonium ion forms in high yield. This intermediate is stable and does not undergo further nucleophilic attack by bromide ion to give the dibromide (J. Am. Chem. Soc. 1985, 107, 45044508). Draw the structure of th

Organic Chemistry 2
The following table provides relative rates of oxymercuration for a variety of alkenes with mercuric acetate (J. Am. Chem. Soc. 1989, 111, 14141418). Provide structural explanations for the trend observed in the relative rates of reactivity. Alkenes Relative Reactivity CH2 C(CH3)(CH2CH2CH3), 1 CH2 CH

Organic Chemistry 2
Diisopinocampheylborane (Ipc2BH) is a chiral organoborane, readily employed for the production of many asymmetric products used in total synthesis. It is a crystalline material that can be prepared as a single enantiomer via the hydroboration of two equivalents of a-pinene with borane (J. Org. Chem.

Organic Chemistry 2
9-Borabicyclo[3.3.1]nonane (9-BBN) is a reagent commonly used in the hydroboration of alkynes (Section 10.7), but it can also be employed in reactions with alkenes. The following table provides the relative rates of hydroboration (using 9-BBN) for a variety of alkenes (J. Am. Chem. Soc. 1989, 111, 14

Organic Chemistry 2
Compound 1 undergoes syn-dihydroxylation to give diastereomers 2 and 3: OH OH OH + HO OH HO OH 1 2 3 The ratio of products was found to be highly sensitive to the conditions employed (Tetrahedron Lett. 1997, 38, 50275030). Under typical catalytic conditions (NMO and catalytic OsO4), the ratio of comp

Organic Chemistry 2
Propose a plausible mechanism for the following transformation, which was used as the key step in the formation of the natural product heliol (Org. Lett. 2012, 14, 29292931): Challenge Problems 463 OH HO CH3CN O + enantiomer H3O+

Organic Chemistry 2
Zaragozic acids are a group of structurally related, natural products that were first isolated from fungal cultures in 1992. These compounds have been shown to reduce cholesterol levels in primates, an observation that has fueled interest in the synthesis of zaragozic acids and their derivatives. Dur

Organic Chemistry 2
When alcohol 1 is treated with propionaldehyde in the presence of mercuric acetate, two initial intermediates are formed (A and B). But from these, only one product results: compound A forms a cyclic product, while B does not (Org. Lett. 2000, 2, 403405): R OH R O OH Et Et O R = C5H12 Hg(OAc) 2 O O H

Organic Chemistry 2
Monensin is a potent antibiotic compound isolated from Streptomyces cinnamonensis. The following reaction was employed during W. C. Stills synthesis of monensin (J. Am. Chem. Soc. 1980, 102, 21182120). Sodium bicarbonate (NaHCO3) functions as a mild base to deprotonate the carboxylic acid group. The

Organic Chemistry 2
Reserpine can be isolated from the extracts of the Indian snakeroot Rauwolfia serpentina and has been used in the effective treatment of mental disorders. R. B. Woodward employed the following reaction sequence in his classic 1958 synthesis of reserpine (Tetrahedron 1958, 2, 157). After compound 1 wa