
Concept explainers
Interpretation:
The structure of the product formed as a result of heating
Concept introduction:
Absorption of IR radiation causes excitations of vibrational motion of the atoms in a molecule. The vibrational motion can be of different types. In stretching vibrations, the bond length changes periodically. In bending vibrations, the bond angle or dihedral angle changes periodically. This may be an in-plane vibration or out of plane vibration.
The changes in the vibrational motion of the atoms in a molecule are quantized, i.e., the energy of vibrational motion can only have certain discrete values. In general, the frequency of the quantum of radiation absorbed and the frequency of vibration are the same.
The energy needed to excite molecular vibrations depends on the bond strength as a bond can be considered to behave like a spring. In turn, this also means it depends on the mass of the atoms that form the bond. In effect, this means the absorption peaks in the IR spectrum are characteristic of the bond between a particular pair of atoms. They are characteristic of the
An IR spectrum records percent transmittance as a function of the wavenumber
The index of hydrogen deficiency (IHD) of a molecule is calculated as the difference between the number of hydrogen atoms in the compound and the number of hydrogen atoms in the corresponding saturated compound divided by two. A double bond and a ring individually contribute one to IHD. A triple bond gives two to IHD.
Heating an alkyl bromide with a strong base like NaOH leads to an E2 elimination.

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Chapter 15 Solutions
Organic Chemistry: Principles And Mechanisms
- Determine if the following salt is neutral, acidic or basic. If acidic or basic, write the appropriate equilibrium equation for the acid or base that exists when the salt is dissolved in aqueous solution. If neutral, simply write only NR. Be sure to include the proper phases for all species within the reaction LiNO3arrow_forwardAn unknown weak acid with a concentration of 0.410 M has a pH of 5.600. What is the Ka of the weak acid?arrow_forward(racemic) 19.84 Using your reaction roadmaps as a guide, show how to convert 2-oxepanone and ethanol into 1-cyclopentenecarbaldehyde. You must use 2-oxepanone as the source of all carbon atoms in the target molecule. Show all reagents and all molecules synthesized along the way. & + EtOH H 2-Oxepanone 1-Cyclopentenecarbaldehydearrow_forward
- R₂ R₁ R₁ a R Rg Nu R₂ Rg R₁ R R₁₂ R3 R R Nu enolate forming R₁ R B-Alkylated carbonyl species or amines Cyclic B-Ketoester R₁₁ HOB R R₁B R R₁₂ B-Hydroxy carbonyl R diester R2 R3 R₁ RB OR R₂ 0 aB-Unsaturated carbonyl NaOR Aldol HOR reaction 1) LDA 2) R-X 3) H₂O/H₂O ketone, aldehyde 1) 2°-amine 2) acid chloride 3) H₂O'/H₂O 0 O R₁ R₁ R R₁ R₁₂ Alkylated a-carbon R₁ H.C R₁ H.C Alkylated methyl ketone acetoacetic ester B-Ketoester ester R₁ HO R₂ R B-Dicarbonyl HO Alkylated carboxylic acid malonic ester Write the reagents required to bring about each reaction next to the arrows shown. Next, record any regiochemistry or stereochemistry considerations relevant to the reaction. You should also record any key aspects of the mechanism, such as forma- tion of an important intermediate, as a helpful reminder. You may want to keep track of all reactions that make carbon-carbon bonds, because these help you build large molecules from smaller fragments. This especially applies to the reactions in…arrow_forwardProvide the reasonable steps to achieve the following synthesis.arrow_forwardIdentify which compound is more acidic. Justify your choice.arrow_forward
- Provide the reasonable steps to achieve the following synthesis.arrow_forwardWhen anisole is treated with excess bromine, the reaction gives a product which shows two singlets in 1H NMR. Draw the product.arrow_forward(ii) Draw a reasonable mechanism for the following reaction: CI NaOH heat OH (hint: SNAr Reaction) :arrow_forward
- Organic ChemistryChemistryISBN:9781305580350Author:William H. Brown, Brent L. Iverson, Eric Anslyn, Christopher S. FootePublisher:Cengage Learning
