Interpretation:
Draw the structure of pre-
Concept introduction:
The type of
Interpretation:
Draw the structure of pre-polymer and show the cross-linking effect of addition of pre-polymer to triamine.
Concept introduction:
The type of polymerization occurring here is condensation polymerization. In this type of polymerization, two monomers react together to give rise to polymeric product by the release of small molecule. In this reaction the molecule which is released during this reaction is sodium chloride (NaCl).
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Organic Chemistry
- Epoxy adhesives are prepared in two steps. SN2 reaction of the disodium salt of bisphenol A with epichlorohydrin forms a prepolymer, which is then cured by treatment with a triamine such as H2NCH2CH2NHCH2CH2NH2. Draw structures to show how addition of the triamine results in a strengthening of the polymer.arrow_forwardCH3 Ph3P-CHCH3 H3C H3C Aldehydes and ketones are converted into alkenes by means of a direct nucleophilic addition called the Wittig reaction. In the reaction, a triphenylphosphorine ylide, also called a phosphorane, adds to an aldehyde/ketone to give a four-membered cyclic intermediate called an oxaphosphetane. The oxaphosphetane is not isolated but instead spontaneously decomposes to release triphenylphosphine oxide and an alkene. Ph3P-CHCH3 H3C The ylide is formed by reaction of triphenylphosphine, a good nucleophile, with a primary alkyl halide in an S 2 reaction, followed by deprotonation of the carbon with a strong base, such as butyllithium. The carbonyl carbon and the carbon originally bonded to the halogen become the two carbons with the double bond in the product alkene :0: CH3 Com The real value of the Wittig reaction lies in its ability to yield an alkene of predictable structure, as the C-C bond is precisely where the C=O bond was in the reactant and no isomers (other than…arrow_forwardGive TWO reagents to prepare cyclopentanone from adipic acid.arrow_forward
- OH KI, Oxone H₂O 22 °C, 1 hr Scheme 1: lodolactionization starting materials and reaction conditionsarrow_forwardOne frequently used method for preparing methyl esters is by reaction of carboxylic acids with diazomethane, CH2N2. The reaction occurs in two steps: (l) protonation of diazomethane by the carboxylic acid to yield methyldiazonium ion, CH3N2+, plus a carboxylate ion; and (2) reaction of the carboxylate ion with CH3N2+. (a) Draw two resonance structures of diazomethane, and account for step 1. (b) What kind of reaction occurs in step 2?arrow_forwardPolycarbonates (Section 29.5C) are also formed by using a nucleophilic aromatic substitution route (Section 22.3B) involving aromatic difluoro monomers and carbonate ion. Propose a mechanism for this reaction.arrow_forward
- The pyrolysis of acetic esters to give an alkene and acetic acid is thought to involve a planar transition state and cyclic redistribution of (4n + 2) electrons. Propose a mechanism for pyrolysis of the following ester.arrow_forwardSeveral diamines are building blocks for the synthesis of pharmaceuticals and agro-chemicals. Show how both 1,3-propanediamine and 1,4-butanediamine can be prepared from acrylonitrile.arrow_forwardDihydropyran is synthesized by treating tetrahydrofurfuryl alcohol with an arenesulfonic acid, ArSO3H. Propose a mechanism for this conversion.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_forwardSharpless epoxidation of allylic alcohol X forms compound Y. Treatment of Y with NaOH and C6H5SH in an alcohol–water mixture forms Z. Identify the structure of Y and draw a mechanism for the conversion of Y to Z. Account for the stereochemistry of the stereogenic centers in Z. Z has been used as an intermediate in the synthesis of chiral carbohydrates.arrow_forwardIsoerythrogenic acid, C18H26O2, is an acetylic fatty acid that turns a vivid blue on exposure to UV light. On Catalytic hydrogenation over a palladium catalyst, five molar equivalents of hydrogen are absorbed, and stearic acid, CH3(CH2)16CO2H, is produced. Ozonolysis of isoerythrogenic acid yields the following products: formaldehyde, CH2O, malonic acid, HO2CCH2CO2H, adipic acid, HO2C(CH2)4CO2H, and the aldehyde carboxylic acid, OHC(CH2)6CO2H. Provide a structure for isoerythrogenic acid.arrow_forward
- Organic ChemistryChemistryISBN:9781305580350Author:William H. Brown, Brent L. Iverson, Eric Anslyn, Christopher S. FootePublisher:Cengage Learning