Organic Chemistry 6th Edition solutions

Organic Chemistry 6
Account for the fact that treatment of tert-butyl methyl ether with a limited amount of concentrated HI gives methanol and tert-butyl iodide rather than methyl iodide and tert-butyl alcohol.

Organic Chemistry 6
Draw structural formulas for the major products of each reaction. CH3 (Excess) (a) CH3COCH3 1 HBr (b) (Excess) 1 HBr CH3 O

Organic Chemistry 6
The trimethylsilyl protecting group is easily removed in aqueous solution containing a trace of acid. Propose a mechanism for this reaction. (Note that a TBDMS protecting group is stable under these conditions because of the greater steric crowding around silicon created by the t-butyl group.)

Organic Chemistry 6
Consider the possibilities for stereoisomerism in the bromohydrin and epoxide formed from trans-2- butene. (a) How many stereoisomers are possible for the bromohydrin? Which of the possible bromohydrin stereoisomers are formed by treating trans-2-butene with bromine in water? (b) How many stereoisome

Organic Chemistry 6
Draw the expected products of Sharpless epoxidation of each allylic alcohol using (1)-diethyl tartrate as the chiral catalyst. HO HO OCH3

Organic Chemistry 6
Write names for these compounds. Where possible, write both IUPAC names and common names. (a) O (b) OCH (c) 3 O OH O O O (d) (h) O O (e) (f) S (g) O

Organic Chemistry 6
Draw structural formulas for these compounds. (a) 2-(1-Methylethoxy)propane (b) trans-2,3- Diethyloxirane (c) trans -2-Ethoxycyclopentanol (d) Ethenyloxyethene (e) Cyclohexene oxide (f ) 3- Cyclopropyloxy-1-propene (g) (R)-2-Methyloxirane (h) 1,1-Dimethoxycyclohexane

Organic Chemistry 6
Each compound given in this problem is a common organic solvent. From each pair of compounds, select the solvent with the greater solubility in water. (a) CH2Cl2 and EtOH (b) Et2O and EtOH (d) O (c) Et2Oand Et2O and

Organic Chemistry 6
Account for the fact that tetrahydrofuran (THF) is very soluble in water, whereas the solubility of diethyl either in water is only 8 g/100 mL water.

Organic Chemistry 6
Because of the Lewis base properties of ether oxygen atoms, crown ethers are excellent complexing agents for Na1, K1, and NH4 1. What kind of molecule might serve as a complexing agent for Cl2 or Br2?

Organic Chemistry 6
Write equations to show a combination of reactants to prepare each ether. Which ethers can be prepared in good yield by a Williamson ether synthesis? If there are any that cannot be prepared by the Williamson method, explain why not. (a) O (b) O (c) OMe O (d) (e) (f) OEt O

Organic Chemistry 6
Draw structural formulas for the products formed when each compound is heated at refl ux in concentrated HI. O O (a) O O O (b) (c) (d)

Organic Chemistry 6
Following is an equation for the reaction of diisopropyl ether and oxygen to form a hydroperoxide. Diisopropyl ether A hydroperoxide O 1 O2 O O OH Formation of an ether hydroperoxide is a radical chain reaction. (a) Write a pair of chain propagation steps that accounts for the formation of this ether

Organic Chemistry 6
Triethanolamine, (HOCH2CH2)3N, is a widely used biological buffer, with maximum buffering capacity at pH 7.8. Propose a synthesis of this compound from ethylene oxide and ammonia.

Organic Chemistry 6
Ethylene oxide is the starting material for the synthesis Cellosolve, an important industrial solvent. Propose a mechanism for this reaction. H2C CH2 Oxirane (Ethylene oxide) 2-Ethoxyethanol (Cellosolve) H2SO4 1 CH3CH2OH CH3CH2OCH2CH2OH

Organic Chemistry 6
Ethylene oxide is the starting material for the synthesis of 1,4-dioxane. Propose a mechanism for each step in this synthesis. O OH OH HO HO O O 1,4-Dioxane H1 H1 1 O

Organic Chemistry 6
Propose a synthesis for 18-crown-6. If a base is used in your synthesis, does it make a difference whether it is lithium hydroxide or potassium hydroxide?

Organic Chemistry 6
Predict the structural formula of the major product of the reaction of 2,2,3- trimethyloxirane with each set of reagents. (a) MeOH/MeO2Na1 (b) MeOH/H1 (c) Me2NH

Organic Chemistry 6
The following equation shows the reaction of trans-2,3-diphenyloxirane with hydrogen chloride in benzene to form 2-chloro-1,2-diphenylethanol. trans-2,3-Diphenyloxirane 2-Chloro-1,2- diphenylethanol C6H5 H H C6H5 C C 1 HCl O C6H5CH9CHC6H5 HO Cl (a) How many stereoisomers are possible for 2-chloro-1,2

Organic Chemistry 6
Propose a mechanism to account for this rearrangement. O BF3 Tetramethyloxirane 3,3-Dimethyl-2- butanone O

Organic Chemistry 6
Acid-catalyzed hydrolysis of the following epoxide gives a trans diol. Only this glycol is formed H2SO4 O H 1 H2O CH3 HO HO H 1 CH3 CH3 HO HO H This glycol is not formed Of the two possible trans diols, only one is formed. How do you account for this stereoselectivity?

Organic Chemistry 6
Following are two reaction sequences for converting 1,2-diphenylethylene into 2,3-diphenyloxirane. 2,3-Diphenyloxirane 1,2-Diphenylethylene RCO3H PhCH9CHPh PhCH"CHPh O PhCH9CHPh O 2,3- Diphenyloxirane 1. Cl2, H2O 2. CH3O2Na1 Suppose that the starting alkene is trans-1,2- diphenylethylene. (a) What is

Organic Chemistry 6
The following enantiomer of a chiral epoxide is an intermediate in the synthesis of the insect pheromone frontalin. OH OO O Show how this enantiomer can be prepared from an allylic alcohol, using the Sharpless epoxidation.

Organic Chemistry 6
Human white cells produce an enzyme called myeloperoxidase. This enzyme catalyzes the reaction between hydrogen peroxide and chloride ion to produce hypochlorous acid, HOCl, which reacts as if it were Cl1OH2. When attacked by white cells, cholesterol gives a chlorohydrin as the major product. Cholest

Organic Chemistry 6
Propose a mechanism for the following acid-catalyzed rearrangement. H2SO4, THF O O

Organic Chemistry 6
Show reagents and experimental conditions to synthesize the following compounds from 1-propanol (any derivative of 1-propanol prepared in one part of this problem may be used for the synthesis of another part of the problem). (a) Propanal (b) Propanoic acid (c) Propene (d) 2-Propanol (e) 2- Bromoprop

Organic Chemistry 6
Starting with cis-3-hexene, show how to prepare the following diols. (a) Meso 3,4-hexanediol (b) Racemic 3,4-hexanediol

Organic Chemistry 6
Show reagents to convert cycloheptene to each of the following compounds. (d) (g) (j) (k) (h) (b) (c) (i) (m) (n) (a) (e) (f) (l) O O H H SEt OH OH OH O NH2 O OMe Br OH O OH OH OH OMe OH CN NH2 OH OH C#CCH3 OH

Organic Chemistry 6
Show reagents to convert bromocyclopentane to each of the following compounds. O O H H (a) (b) (e) (i) (g) (f) (d) (c) (j) (h) (k) OH OH OH OH Br O OH NEt2 OH OMe O OMe OH C#CH

Organic Chemistry 6
Given the following retrosynthetic analysis, show how to synthesize the target molecule from styrene and 1-chloro-3-methyl-2-butene. O HO Cl OH O Styrene 1-Chloro-3-methyl-2-butene 1

Organic Chemistry 6
Starting with acetylene and ethylene oxide as the only sources of carbon atoms, show how to prepare these compounds. (a) 3-Butyn-1-ol (b) 3-Hexyn-1,6-diol (c) 1,6-Hexanedio

Organic Chemistry 6
Following are the steps in the industrial synthesis of glycerin. Cl2 heat Cl2 NaOH, H2O , H2O CH2"CHCH3 A (C3H5Cl) Ca(OH)2 heat H2O, HCl C (C3H7ClO2) D (C3H6O2) HOCH2CHCH2OH 1,2,3-Propanetriol (glycerol, glycerin) B (C3H6O) Propene OH Provide structures for all intermediate compounds (AD) and describ

Organic Chemistry 6
Gossyplure, the sex pheromone of the pink bollworm, is the acetic Following is a retrosynthetic analysis for (7Z, 11E)-7,11-hexadecadien-1-ol, which then led to a successful synthesis of gossyplure. O9Si9t-Bu OH OH H 1 Br OH Br 1 H OH 1 H Br Br 1 H H O Me Me O9Si9t-Bu Me Me O9Si9t-Bu Me Me 1 2 3 4 5

Organic Chemistry 6
Epichlorohydrin (Section 11.10) is a valuable synthetic intermediate because each of its three carbons contains a reactive group. Following is the fi rst step in its synthesis from propene. Propose a mechanism for this step. 5008C 1 Cl Propene 3-Chloropropene (Allyl chloride) Cl2 1 HCl

Organic Chemistry 6
Each of these drugs contains one or more building blocks derived from either ethylene oxide or epichlorohydrin. Cl N N H Moclobemide (an antidepressant) O O OH (a) NH2 N H Atenolol (an antihypertensive) O O (b) O O Me Me OMe Diphenhydramine (Benadryl, an antihistamine) Spasmolytol (an antispasmodic)

Organic Chemistry 6
Aldehydes and ketones react with one molecule of an alcohol to form compounds called hemiacetals, in which there is one hydroxyl group and one ether-like group. Reaction of a hemiacetal with a second molecule of alcohol gives an acetal and a molecule of water. We study this reaction in Chapter 16. "O

Organic Chemistry 6
Use the roadmap you made for problem 6.54, 7.29, 8.28, 9.54, and 10.50, and update it to contain the reactions in the Key Reactions section of this chapter. Because of their highly specifi c nature, do not use reactions 2, 8, and 10 on your roadmap.

Organic Chemistry 6
Write the products of the following sequences of reactions. Refer to your roadmap to see how the combined reactions allow you to navigate between the different functional groups. (a) 1. Na8 2. OH Br An alcohol (b) Cl 1. 1 Equivalent of KOtBu 2. mCPBA 3. H3O /H2O 1 A haloalkane (c) 1. BH3 2. H2O2/NaOH

Organic Chemistry 6
Using your roadmap as a guide, show how to convert 1-butene into dibutyl ether. You must use 1- butene as the source of all carbon atoms in the dibutyl ether. Show all required reagents and all molecules synthesized along the way. 1-Butene Dibutyl ether ? O

Organic Chemistry 6
Using your roadmap as a guide, show how to convert cyclohexanol into racemic trans-1,2- cyclohexanediol. Show all required reagents and all molecules synthesized along the way. ? OH OH Cyclohexanol Trans-1,2-cyclohexanediol (racemic) OH OH OH

Organic Chemistry 6
Using your roadmap as a guide, show how to convert 1-butanol and ethanol into racemic 2-ethoxy-1- butanol. You must use 1-butanol and ethanol as the source of all carbon atoms in the ether product. Show all required reagents and all molecules synthesized along the way. ? O O OH OH OH OH 1- Butanol 1

Organic Chemistry 6
During the synthesis of the antiasthmatic drug montelukast (Singulair), a silyl ether protecting group is used to mask the reactivity of an OH group. The silyl group chosen is the tert-butyldimethylsilyl (TBDMS) group. Draw the product of the following transformation, assuming the TBDMS-Cl reagent re

Organic Chemistry 6
The Sharpless epoxidation is used when a single enantiomer product is required. Predict the structure of the predominant product of the following transformation. (2)-Diethyl tartrate Ti(O9iPr)4 tert-Butyl hydroperoxide O Si O OH