Concept explainers
Interpretation:
The structure of the given compound and the mechanism of the given reaction are to be determined.
Concept introduction:
To determine the actual structure of organic compounds, IR spectroscopy (Infrared spectroscopy) is an invaluable tool. The use of
Transesterification is a process in which the R group of an ester is exchanged with an R group of an alcohol. This process takes place in the presence of a base catalyst or an acid catalyst.
Want to see the full answer?
Check out a sample textbook solutionChapter 23 Solutions
Organic Chemistry
- Gamma(y)-amino butyric acid (GABA) is a neurotransmitter (a chemical that is used to send signals from one neuron to another) of the mammalian central nervous system. In order to understand how GABA works, conformationally restricted analogues, such as compound 1, have been made. During a synthesis of compound 1, compound 2 was subjected to allylic bromination using NBS and a radical initiator (AIBN) instead of light (Aust. J. Chem. 1981, 34, 2231-2236). H₂N. CH3 GABA CO₂H CH3 dddd CH3 H₂N Modify the structures given below to draw all eight possible allylic bromides that can be formed when compound 2 undergoes allylic bromination, considering all possible regiochemical and stereochemical outcomes. You can use the single bond tool to add/remove pi bonds. CH3 CO₂H CH3 solddd CH3 CH3 2 CH₂ CO₂Etarrow_forwardThe following substances can be prepared by a nucleophilic addition reaction between an aldehyde or ketoneand a nucleophile. Identify the reactants from which they were prepared. If the substance is an acetal, identifythe carbonyl compound and the alcohol; if it is an imine or enamine, identify the carbonyl compound and theamine. You do not have to consider stereochemistry. In cases where there is more than one answer, just giveone. Use Grignard reagents when an organometallic reagent is required. Draw the Grignard reagent as acovalent magnesium bromide.arrow_forwardAn amine of unknown structure contains one nitrogen and nine carbon atoms. The 13C-NMR spectrum shows only five signals, all between 20 and 60 ppm. Three cycles of Hofmann elimination sequence [(1) CH3I; (2) Ag2O, H3O; (3) heat] give trimethylamine and 1,4,8-nonatriene. Propose a structural formula for the amine.arrow_forward
- Following is a synthesis for toremifene, a nonsteroidal estrogen antagonist whose structure is closely related to that of tamoxifen. (a) This synthesis makes use of two blocking groups, the benzyl (Bn) group and the tetrahydropyranyl (THP) group. Draw a structural formula of each group and describe the experimental conditions under which it is attached and removed. (b) Discuss the chemical logic behind the use of each blocking group in this synthesis. (c) Propose a mechanism for the conversion of D to E. (d) Propose a mechanism for the conversion of F to toremifene. (e) Is toremifene chiral? If so, which of the possible stereoisomers are formed in this synthesis?arrow_forwardThe following sequence of steps converts (R)-2-octanol to (S)-2-octanol. Propose structural formulas for intermediates A and B, specify the configuration of each, and account for the inversion of configuration in this sequence.arrow_forwardThe base-promoted rearrangement of an -haloketone to a carboxylic acid, known as the Favorskii rearrangement, is illustrated by the conversion of 2-chlorocyclohexanone to cyclopentanecarboxylic acid. It is proposed that NaOH first converts the a-haloketone to the substituted cyclopropanone shown in brackets and then to the sodium salt of cyclopentanecarboxylic acid. (a) Propose a mechanism for base-promoted conversion of 2-chlorocyclohexanone to the proposed intermediate. (b) Propose a mechanism for base-promoted conversion of the proposed intermediate to sodium cyclopentanecarboxylate.arrow_forward
- Several sulfonylureas, a class of compounds containing RSO2NHCONHR, are useful drugs as orally active replacements for injected insulin in patients with adult-onset diabetes. These drugs decrease blood glucose concentrations by stimulating b cells of the pancreas to release insulin and by increasing the sensitivity of insulin receptors in peripheral tissues to insulin stimulation. Tolbutamide is synthesized by the reaction of the sodium salt of p-toluenesulfonamide and ethyl N-butylcarbamate . Propose a mechanism for this step.arrow_forwardWhich of the following reactions will synthesize phenol from benzene? 1) HNO3 + H2SO4; 2) Fe, HCl; 3) NaNO2, HCl, 0-10 oC; 4) warm H2SO4 and H2O 1) HNO3 + H2SO4; 2) Fe, HCl; 3) NaNO2, HCl, 0-10 oC; 4) CuCN; 5) dilute acid and heat 1) Acetyl chloride & AlCl3; 2) bleach 1) Ph-N2+ + KI; 2) BrMgCH=CH2 in ether, followed by H3O+; 3) warm, conc'd KMnO4 1) Cl-CH(CH3)-CH2CH2CH3 + FeBr3; 2) hot, conc'd KMnO4arrow_forwardWrite down an organic chemistry mechanism (use curly arrows) for the transformation of benzamide to benzoic acid, via its sodium salt.arrow_forward
- Q5:- Give structures and names of the principal organic reactants and products of the following reactions. a- pentinoic acid from butanol b- Preparation of acid anhydrides Q6:- Rank the following substances in order of increasing acidity , Justify your choice. benzoic acid, p-chlorobenzoic acid , 2,4-dichlorobenzoic acid , 2,4,6-trichlorobenzoic acidarrow_forwardIs esmolol chiral? If so, which of the possible stereoisomers are formed in this synthesis?arrow_forwardWhen acetonitrile is treated with concentrated sulfuric acid and tert-butanol, followed by water, a product is formed whose 'H NMR spectrum exhibits the following three signals: singlet, 1.3 ppm, 9 H; singlet, 2.0 ppm, 3 H; and broad singlet, 8.2 ppm, 1 H. Its IR spectrum exhibits one broad absorption of medium intensity between 3300 and 3500 cm-1, and a narrow, intense absorption near 1650 cm¯1. A key intermediate is shown. Draw the structure of the product, and draw the complete, detailed mechanism for the reaction. CH3 CH3 H2SO4 (conc) H2O ? + H3C H3C H3C-C=Ñ-c `CH3 CH3 HOarrow_forward
- Organic ChemistryChemistryISBN:9781305580350Author:William H. Brown, Brent L. Iverson, Eric Anslyn, Christopher S. FootePublisher:Cengage LearningIntroduction to General, Organic and BiochemistryChemistryISBN:9781285869759Author:Frederick A. Bettelheim, William H. Brown, Mary K. Campbell, Shawn O. Farrell, Omar TorresPublisher:Cengage Learning