Questions and Answers of Organic Chemistry 12th

Hydrolysis of atropine gives tropine and (±)-tropic acid. (a) What are their structures?(b) Even though tropine has a chirality center, it is optically inactive. Explain. (c) An isomeric
Give formulas and names for compounds A and B: -5a-Cholest-2-ene CH₂COOH A (an epoxide) HBr B
(a) Write structural formulas for portions of the chain of the atactic, syndiotactic, and iso-tactic forms of polystyrene. (b) If solutions were made of each of these forms of polystyrene, which
(a) Show the orbitals involved in the following thermal electrocyclic reaction.(b) Do the groups rotate in a conrotatory or disrotatory manner? CH₂ CH₂ CH₂ TH H CH₂ 200
Can you suggest a method for carrying out a stereospecific conversion of trans, trans-2,4-hexadiene into cis,trans-2,4-hexadiene?
For each of the following reactions, (1) state whether the conrotatory or disrotatory motion of the groups is involved, and (2) state whether you would expect the reaction to occur under the
Give the stereochemistry of the product that you would expect from each of the following electrocyclic reactions.
Can you suggest a stereospecific method for converting trans-5,6-dimethyl-1,3-cyclohexadiene into cis-5,6-dimethyl-1,3-cyclohexadiene?
When compound A is heated, compound B can be isolated from the reaction mixture. A sequence of two electrocyclic reactions occurs; the first involves a 4π-electron system, and the second involves a
Predict the product from each of the following reactions.(a)(b)(c)(d) heat
What reactant could lead to each product by either a Cope or Claisen rearrangement?(a)(b) ? heat
Nicotine has been synthesized by the following route. All of the steps involve reactions that we have seen before. Suggest reagents that could be used for each. OEt + CH3 (a) (b) CH3
The principal alkaloid of Atropa belladonna is the optically active alkaloid hyoscyamine. During its isolation hyoscyamine is often racemized by bases to optically inactive atropine.(a) What
In 1891 G. Merling transformed tropine into 1,3,5-cycloheptatriene (tropylidene) through the following sequence of reactions:Write out all of the reactions that take place. Tropine
Many alkaloids appear to be synthesized in plants by reactions that resemble the Mannich reaction. Recognition of this (by R. Robinson in 1917) led to a synthesis of tropinone that takes place under
Papaverine has been synthesized by the following route:Outline the reactions involved. CH₂O CH₂O NH₂ CH₂O CH₂O CI НО- C20H25 NO5
One of the important steps in Gates’ synthesis of morphine involved the following transformation:Suggest how this step was accomplished. CH₂O CH₂O NC CH₂O CH₂O NC-
When farnesol is treated with sulfuric acid, it is converted to bisabolene. Outline a possible mechanism for this reaction. Farnesol H₂SO4 Bisabolene
When morphine reacts with 2 mol of acetic anhydride, it is transformed into the highly addictive narcotic heroin. What is the structure of heroin?
Gramin has been synthesized by heating a mixture of indole, formaldehyde, and dimethylamine.(a) What general reaction is involved here? (b) Outline a reasonable mechanism for the gramine
When the following molecule was exposed to the Grubbs I initiator at different concentrations, different products resulted. How can you account for these different outcomes?(a)(b)(c) Grubbs I (29 mol
Draw the structure of a phospholipid (from any of the subclasses of phospholipids) that contains one saturated and one unsaturated fatty acid.(a) Draw the structure of all of the products that would
Given that p-Benzoquinone and 1,4-naphthoquinone act as dienophiles in Diels–Alder reactions. Give the structures of the products of the following reactions: (a) 1,4-Naphthoquinone +
In “The Chemistry of… Complex Cross Couplings” we showed a Heck reaction used in the synthesis of ecteinascidin 743, a natural compound with anticancer activity isolated from the marine
For each of the following complexes, determine the oxidation state of the metal and the total number of valence electrons it possesses.(a)(b)(c) Ph.P H Ph P CI PPh mee Rh
What is the product of the following Suzuki–Miyaura coupling? Br B(OR)2 + Pd catalyst Base
Starting with 1-butanol and using any other required reagents, outline a synthesis of each of the following compounds. You need not repeat steps carried out in earlier parts of this problem.(a) Butyl
What starting materials could be used to synthesize the following compound by a Suzuki–Miyaura coupling? H.
What is the product of each of the following reactions? (a)(b)(c)(d) SnBu3 Pd catalyst
Provide the products of each of the following reactions.(a)(b) Ho 6 H+ Br- 앤 OH Cul, Pd catalyst Base (an amine)
What starting materials could be used to synthesize each of the following compounds by a Sonogashira coupling reaction?(a)(b) CI
Show how 1-bromobutane could be converted to the Gilman reagent lithium dibutylcuprate and how you could use it to synthesize each of the following compounds.(a)(b)
Heating acetone with an excess of phenol in the presence of hydrogen chloride is the basis for an industrial process used in the manufacture of a compound called “bisphenol A.” (Bisphenol A,
For each of the following complexes, determine the oxidation state of the metal, the total number of valence electrons it possesses, and state whether the metal is coordinatively saturated or
The sedative-hypnotic ethinamate can be synthesized by the following route. Provide structures for ethinamate and the intermediates A and B: Cyclohexanone (1) HC=CNa, (2) H₂O+ A (C₂H12O) CICOCI B
How would you synthesize each of the following using a Gilman reagent?(a)(b)(c)
Show how you could potentially use two different cross-coupling reactions to prepare each of the following.(a)(b)(c) H₂CO O
Show how you would modify the synthesis given in the previous problem to synthesize the following drugs:(a) Bromodiphenhydramine (an antihistamine), where R1 = Br, R2 = H(b) Orphenadrine (an
Predict the product(s) for each of the following reactions:(a)(b)(c) (d) D₂ Wilkinson's catalyst
Outlined here is a synthesis of 2-methyl-3-oxocyclopentanecarboxylic acid. Give the structure of each intermediate: Br OEt EtO OEt, EtO A (C₁2H2006) CN, EtO
Predict the product from each of the following reactions.(a)(b)(c) Br + B(OH)₂ Pd catalyst
The tranquilizing drug meprobamate (Equanil or Miltown) can be synthesized from 2-methylpentanal as follows. Give structures for meprobamate and for the intermediates A–C: H HCHO, HO [A
In general, intramolecular reactions that form rings are often disfavored entropically because it makes a flexible starting material more rigid. In the case of ring-closing metathesis, however, the
The tranquilizing drug meprobamate (Equanil or Miltown) can be synthesized from 2-methylpentanal as follows. Give structures for meprobamate and for the intermediates A–C: О HCHO, HO H [A
Cross-coupling reactions have been used for the synthesis of polymers. Predict the structure of the polymer that would result from each of these reactions. Designate the repeating unit of the polymer
What are compounds A–C? Compound C is useful as an insect repellent. CH₂CH₂CH₂OH A (C7H12O4) SOCI
What polymer would be formed from each of the following strained alkenes through ROMP using an appropriate metal alkylidene catalyst?(a)(b)
Outlined here is the synthesis of a central nervous system stimulant called fencamfamine. Provide structural formulas for each intermediate and for fencamfamine itself: 1,3-Cyclopentadiene + NO₂ A
Write a mechanism that can account for the formation of the following product through a series of olefin metathesis reactions from the indicated starting material. N Ru= N
What are compounds A and B? Compound B has a strong IR absorption band in the 1650–1730 cm−1 region and a broad strong band in the 3200–3550 cm−1 region. 1-Methylcyclohexene (1)
Write the mechanism for the following Heck reaction that can explain the final alkene stereochemistry and why the Pd species can promote the reaction to go to completion in only catalytic quantities.
The Dow process for synthesizing phenol, which involves the reaction of chlorobenzene with aqueous sodium hydroxide at high temperature and pressure, produces both diphenyl ether (1) and
For each of the following, identify the product (represented by A, B, C, and D) that would be formed through the indicated sequence of steps from the given starting material.(a)(b)(c)(d) CI (1)
In 1985, T. Katz (Columbia University) discovered that alkynes could participate in metathesis reactions via similar mechanistic processes as alkenes. Below is a reaction involving both an alkyne and
Adult African dwarf crocodiles produce an aromatic ketone called dianeackerone, named in honor of Diane Ackerman, poet champion of endangered species and biodiversity. Dianeackerone was isolated,
(a) Write as many chemically reasonable syntheses as you can think of for ethyl 2-methylpropyl ether (ethyl isobutyl ether). Be sure that at some point in one or more of your syntheses you utilize
Propose mechanisms for the following reactions.(a)(b) Br OH cat. H₂SO4 Br
During the course of the following Stille coupling, the product shown was formed. How did this result come about? OTBDPS Br CO,CH, NBoc OTBDPS SnBu Pd(PPh,), toluene, 110 °C, 30
Olestra is a fat substitute patented by Procter and Gamble that mimics the taste and texture of triacylglycerols. It is calorie-free because it is neither hydrolyzed by digestive enzymes nor absorbed
The biosynthesis of fatty acids is accomplished two carbons at a time by an enzyme complex called fatty acid synthetase. The biochemical reactions involved in fatty acid synthesis are described in
A certain natural terpene produced peaks in its mass spectrum at m/z 204, 111, and 93 (among others). On the basis of this and the following information, elucidate the structure of this terpene.
Elucidate the structure of the compound that gives the following spectroscopic data. Assign the data to specific aspects of your proposed structure. MS (m/z); 120, 105 (base peak), 77 1H NMR (δ):
(a) Write reactions to show how you could convert 2-methyl-2-butene into 2-methyl-1,3-butadiene.(b) Write reactions to show how you could convert ethylbenzene into the following compound(c) Write
Predict the products of the following reactions.(a)(b) HCI
What products would you expect from the reaction of 1 mol of 1,3-butadiene and each of the following reagents? (a) 1 mol of Cl2(b) 2 mol of Cl2(c) 2 mol of Br2(d) 2 mol of H2, Ni(e) 1 mol of Cl2
Predict the products of the following reactions.(a)(b)(c) HBr -15 °C
For each of the following, identify the product (represented by A and B) that would be formed through the indicated sequence of steps from the given starting material.(a)(b) (1) NaNH,, Etl (2)
Write mechanism arrows for the following step in the chemical synthesis by A. Robertson and R. Robinson (J. Chem. Soc. 1928, 1455–1472) of callistephin chloride, a red flower pigment from the
The following reaction sequence was used by E. J. Corey (J. Am. Chem. Soc. 1969, 91, 5675–5677) at the beginning of a synthesis of prostaglandin F2α and prostaglandin E2. Explain what is
The 1H NMR signals for the aromatic hydrogens of methyl p-hydroxybenzoate appear as two doublets at approximately 7.05 and 8.04 ppm (δ). Assign these two doublets to the respective hydrogens that
The structure of thyroxine, a thyroid hormone that helps to regulate metabolic rate, was determined in part by comparison with a synthetic compound believed to have the same structure as natural
Draw the structure of adenine, a heterocyclic aromatic compound incorporated in the structure of DNA. Identify the nonbonding electron pairs that are not part of the aromatic system in the rings of
Draw structures of the nicotinamide ring in NADH and NAD+ In the transformation of NADH to NAD+, in what form must a hydrogen be transferred in order to produce the aromatic pyridinium ion in NAD+?
Starting with benzene, outline a synthesis of each of the following:(a) Isopropylbenzene(b) tert-Butylbenzene(c) Propylbenzene(d) Butylbenzene(e) 1-tert-Butyl-4-chlorobenzene(f)
Provide a mechanism for the following reaction. 。 C H2SO4, H2O OH
Propose structures for compounds G–I: OH OH concd H₂SO4 60-65 °C G (C6H6S₂O₂) concd HNO3 concd H₂SO H (C6H5NS₂010) H₂O+, H₂O heat I (C6H5NO₂)
Starting with toluene, outline a synthesis of each of the following:(a) m-Chlorobenzoic acid(b) p-Methylacetophenone(c) 2-Bromo-4-nitrotoluene(d) p-Bromobenzoic acid(e)
Provide a mechanism for the following reaction. H2SO4, H2O OH
Starting with aniline, outline a synthesis of each of the following:(a) p-Bromoaniline(b) o-Bromoaniline(c) 2-Bromo-4-nitroaniline(d) 4-Bromo-2-nitroaniline
Predict the outcome of the following reactions: CN CI 2 equiv. KNH₂ lig. NH3, 33 C
Provide a mechanism for the following reaction. NO₂ NO₂ 2 ss-sr NaOCH3 OH NO₂ O=5 S=0 NO₂
Predict the major product from each of the following reactions. H O (1) (2) H₂O+ (3) H₂CrO4 MgBr (excess)
Show how the diketone at the right could be prepared by a condensation reaction: lion to bolo HO R OEt + + R EtOH
For each of the following, identify the product (represented by A, B, C, and D) that would be formed through the indicated sequence of steps from the given starting material. O (1) mCPBA (2) EtMgBr
Synthesize (a) and (b) from cyclopentanone and (c) from diethyl malonate. You may use any other reagents necessary.(a) (b)(c)
Provide a mechanism for the following reaction. 3 NaOH H₂O
For each of the following, identify the product (represented by A, B, C, and D) that would be formed through the indicated the sequence of steps from the given starting material.(a)(b)(c) (d)
Dehydroabietic acid is a natural product isolated from Pinus palustris. It is structurally related to abietic acid, which comes from rosin. The synthesis of dehydroabietic acid (J. Am. Chem. Soc.
Lycopene is a naturally occurring amine. As such, it belongs to the family of natural products called alkaloids. Its synthesis (J. Am.Chem. Soc. 1968, 90, 1647–1648) was accomplished by one of the
Predict the products of the following reactions.(A)(B)(C)(D) O O O (1) NaOEt, EtOH (2) (3) H₂O*
Steroids are an extremely important class of natural and pharmaceutical compounds. Synthetic efforts directed toward steroids have been underway for many years and continue to be an area of important
Outline a racemic synthesis of Darvon (below), an analgesic compound whose use has been discontinued, starting with ethyl phenyl ketone. CH3- N CH3 O ¹C6H5 CH3 C6H5 Tw
For each of the following, identify the product (represented by A and B) that would be formed through the indicated sequence of the steps from the given starting material.(A)(B) Eto (1)
Develop a synthesis for the following molecule using only the indicated materials as sources for the carbon atoms that appear in the final product. As a hint, you will need to draw upon several
Reserpine is a natural product belonging to the family of alkaloids (see Special Topic H in WileyPLUS ). Reserpine was isolated from the Indian snakeroot Rauwolfia serpentina. Clinical applications
(a) Draw mechanisms to account for the following two transformations, each of which leads to the same product. (b) Why are these new products favored over the starting materials under these
(a) A student was given a mixture of two unknown compounds and asked to separate and identify them. One of the compounds was an amine and the other was a neutral compound (neither appreciably acidic
Write a mechanism that explains how the reaction of 1 mol of bromoethane with 1 mol of ammonia can lead to a mixture of ethylamine, diethylamine, triethylamine, and tetraethylammonium bromide rather
Show how N-methyl benzylamine could be synthesized from either methylamine or benzylamine by alkylation of a sulfonamide.
For each of the following questions, please provide a route that could reasonably be expected to convert the starting material into the final product. In each case, more than one reaction is

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