Concept explainers
The heats of combustion of the more and less stable stereoisomers of the
and
Dimethylcyclohexane
Heats of combustion (kJ/mol):
More stable stereoisomer
Less stable stereoisomer
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- Gibbs free energy differences between axial-substituted and equatorial-substituted chair conformations of cyclohexane were given in Table 2.4. (a) Calculate the ratio of equatorial to axial tert-butylcyclohexane at 25C. (b) Explain why the conformational equilibria for methyl, ethyl, and isopropyl substituents are comparable but the conformational equilibrium for tert-butylcyclohexane lies considerably farther toward the equatorial conformation.arrow_forwardClassify the following compounds as E/Z- structures CH3 HO-CH2-CH2 CH2CHCH2OH H2N CH2-CH3 H2N CH=CH2 CH2=CH I CH-CH3 но- CH II CH2-NH2 Br CH2CH2CH2CH3 III CH3 OHarrow_forwardBelow are isomers of tert-butylcyclohexanol in conformational structures. Two are cis-2-tert- butylcyclohexanol and two are cis-3-tert-butylcyclohexanol. Indicate which is the more stable conformation for each pair, and indicate which of all four conformations is the most stable. A OH Ex HO B D OH OHarrow_forward
- Indicate whether the pair of structures shown represent stereoisomers, constitutional isomers, different conformations of the same compound, or the same conformation of a compound viewed from a different perspective. Note that cis, trans isomers are an example of stereoisomers. CI H H " & " H H CH3 НО. CH3 Submit Answer OH Н. H H CH3 HO H Retry Entire Group CI CH3 OH different conformations ✓ 2 more group attempts remainingarrow_forwardDraw all the isomers of C5H₁0. Clearly show stereochemistry if stereoisomers are possible. Step 1: Start by drawing all the isomers with double bonds. • Consider constitutional isomers, then stereoisomers. Step 2: Draw all isomers containing a ring. • Consider constitutional isomers, then stereoisomers. Step 2: Next consider isomers containing a ring. The largest ring possible with this molecular formula contains 5 carbons, while the smallest possible ring contains 3 carbons. Draw an isomer containing a 5-carbon ring. Rings More Select Draw / C H Erase Consider a 4-carbon ring of C5H₁0. Draw stereoisomers, if applicable. Select Draw Rings More C H Erasearrow_forwardConstruct the chair structures with the molecular models for trans-1-ethyl-3-methylcyclohexane. Find the energy of each conformer, the equilibrium constant Keq, and the percentage of each conformer at 25oC. Indicate which conformer is more stable.arrow_forward
- Which has a higher percentage of the diequatorial-substituted conformer compared with the diaxial-substituted conformer: trans-1,4-difluorocyclohexane or cis-1-tert-butyl-3- fluorocyclohexane? O trans-1,4-difluorocyclohexane O cis-1-tert-butyl-3-fluorocyclohexanearrow_forwardC=CH H20, H2SO4 H9SO4 CH3 Alkynes do not react directly with aqueous acid as do alkenes, but will do so in the presence of mercury(II) sulfate as a Lewis acid catalyst. The reaction occurs with Markovnikov regiochemistry, so the OH group adds to the more highly substituted carbon and the H adds to the less highly substituted carbon. The initial product of the reaction is a vinyl alcohol, also called an enol. The enol immediately rearranges to a more stable ketone via tautomerization. Draw curved arrows to show the movement of electrons in this step of the mechanism. Arrow-pushing Instructions H-OH HO: Hjö: C=CH c=CH Hö Hg Hgarrow_forwardHow many degrees of unsaturation (double bond equivalents) does C4H10ClNO have?arrow_forward
- When 1- methyl cyclohexene reacted with HBr, what are the reaction products and show which one is major?arrow_forwardAn alkene having the molecular formula C5H10 is treated sequentially with ozone (O3) and zinc/acetic acid to give the product/s shown. H3C O CH3CHCH + H. Draw a structural formula for the alkene. You do not have to consider stereochemistry. • You do not have to explicitly draw H atoms. In cases where there is more than one answer, just draw one. P opy aste [* Previous Nextarrow_forward1,2,3,4,5,6-Hexachlorocyclohexane shows cis,trans isomerism. At one time, a crude mixture of these isomers was sold as an insecticide. The insecticidal properties of the mixture arise from one isomer, known as lindane, which is cis-1,2,4,5-trans- 3,6-hexachlorocyclohexane. Q.) Draw a structural formula for 1,2,3,4,5,6-hexachlorocyclohexane disregarding, for the moment, the existence of cis,trans isomerism. What is the molecular formula of this compound?arrow_forward
- Organic ChemistryChemistryISBN:9781305580350Author:William H. Brown, Brent L. Iverson, Eric Anslyn, Christopher S. FootePublisher:Cengage Learning