Concept explainers
(a)
Interpretation:
TThe two possible chair conformations for the cis-1-isopropyl-3-methylcyclohexane should be drawn and named every substituent as axial or equatorial and most stable conformer should be selected.
Concept introduction:
when the cyclohexane ring converts from one chair conformation to another, the equatorial hydrogen atoms are converted into axial hydrogen atoms and vice versa.
When the cyclohexane has one substituent then the conformation which contain the substituent in equatorial position is more stable due to less steric strain with axial hydrogen atoms.
When two substituents are present in the structure, in order to find the more stable conformation can be determined by looking at the groups in the axial position.
When a bulkier group present in the axial position, that conformation get less stable.
In cis conformation, both substituents are in the same side.
(b)
Interpretation:
The two possible chair conformations for the cis-4-tert-butylcyclohexanol should be drawn and named every substituent as axial or equatorial and most stable conformer should be selected.
Concept introduction:
when the cyclohexane ring converts from one chair conformation to another, the equatorial hydrogen atoms are converted into axial hydrogen atoms and vice versa.
When the cyclohexane has one substituent then the conformation which contain the substituent in equatorial position is more stable due to less steric strain with axial hydrogen atoms.
When two substituents are present in the structure, in order to find the more stable conformation can be determined by looking at the groups in the axial position.
When a bulkier group present in the axial position, that conformation get less stable.
Want to see the full answer?
Check out a sample textbook solutionChapter 26 Solutions
EBK GENERAL CHEMISTRY
- Which of the following statements is not true regarding the conformation of substituted cyclohexanes? O a. the boat conformation of cyclohexane is usually more stable than the chair conformation O b. ring inversion of cyclohexane between two chair conformations takes place via a boat conformation O c. substituted cyclohexanes are destabilized by 1,3-diaxial interactions d. the relative amount of two conformations of substituted cyclohexanes can be determined from the difference in strain energyarrow_forwardPlace the methyl groups by drawing the axial and equatorial positions on the cyclohexane structure in the chair conformations next to the cyclohexane derivatives named below.arrow_forwardConsider 1,2-dimethylcyclohexane.a. Draw structures for the cis and trans isomers using a hexagon for the six-membered ring.b. Draw the two possible chair conformations for the cis isomer. Which conformation, if either, is more stable?c. Draw the two possible chair conformations for the trans isomer. Which conformation, if either, is more stable?d. Which isomer, cis or trans, is more stable and why?arrow_forward
- 4. Perform a conformational analysis on cyclohexane derivative I. Draw out both possible conformers and circle Using A, U, and G values estimate the energy difference (DG) the preferred (lowest energy) conformer between the two conformers and predict the approximate ratio of the two conformers at room temperature Hj C Br cyclohexane Iarrow_forwardWhat is the preferred IUPAC name of the alkene shown in Figure below? CH3 CH3 CH3 `CH-CH3 A. 1-ethyl-2,4,5-trimethylcyclohexene B. 2-ethyl-1,4,5-trimethylcyclohexene C. 2-ethyl-1,4,5-trimethylcyclohex-1-ene D. 4-ethyl-1,2,5-trimethylcyclohexenearrow_forwardClassify each of the following hydrocarbons as saturated or unsaturated. Ethylcyclopentane Ethylcyclopentene 1,3-butadiene 2-methyl-2-pentene 2-methylcyclopentene 1,2-cyclopentadiene 2,3-dimethylpentanearrow_forward
- Choose among the letters based on the questionsarrow_forwardConsider 1,2-dimethylcyclohexane. a.Draw structures for the cis and trans isomers using a hexagon for the sixmembered ring. b. Draw the two possible chair conformations for the cis isomer. Which conformation, if either, is more stable? c. Draw the two possible chair conformations for the trans isomer. Which conformation, if either, is more stable? d.Which isomer, cis or trans, is more stable and why?arrow_forwardNAME: 1. Draw the 2 chai conformations of cis-1-tert-butyl-2-ethylcyclohexane. Circle the most stable conformation of the moleculearrow_forward
- Draw a chair conformation of cyclohexane with one CH3CH2 group and one CH3 group that ts each description.a. a 1,1-disubstituted cyclohexane with an axial CH3CH2 groupb. a cis-1,2-disubstituted cyclohexane with an axial CH3 groupc. a trans-1,3-disubstituted cyclohexane with an equatorial CH3 groupd. a trans-1,4-disubstituted cyclohexane with an equatorial CH3CH2 grouparrow_forwardConsider pentane, C5H12. Looking through the internal C3-C4single bond, draw thesix Newman projections (where the angle between two bonds as you look through the C3and C4bond is either 0°or 60°of the different conformations. Label the conformers/rotamers using I, II, etc. a.Which conformer is the most stable? the least stable? b.Which rotamer is the anticonformer? the gaucheconformer? c.Draw the anticonformer in saw horse projection.arrow_forwardWhat is the IUPAC name of the following compound? F. а. 1-ethyl-3-fluoro-2,5-dimethylcyclohexane O b. 2-ethyl-6-fluoro-1,4-dimethylcyclohexane c. 3-ethyl-5-fluoro-1,4-dimethylcyclohexane O d. 3-ethyl-1-fluoro-2,5-dimethylcyclohexane Jump to... neworkarrow_forward
- ChemistryChemistryISBN:9781305957404Author:Steven S. Zumdahl, Susan A. Zumdahl, Donald J. DeCostePublisher:Cengage LearningChemistryChemistryISBN:9781259911156Author:Raymond Chang Dr., Jason Overby ProfessorPublisher:McGraw-Hill EducationPrinciples of Instrumental AnalysisChemistryISBN:9781305577213Author:Douglas A. Skoog, F. James Holler, Stanley R. CrouchPublisher:Cengage Learning
- Organic ChemistryChemistryISBN:9780078021558Author:Janice Gorzynski Smith Dr.Publisher:McGraw-Hill EducationChemistry: Principles and ReactionsChemistryISBN:9781305079373Author:William L. Masterton, Cecile N. HurleyPublisher:Cengage LearningElementary Principles of Chemical Processes, Bind...ChemistryISBN:9781118431221Author:Richard M. Felder, Ronald W. Rousseau, Lisa G. BullardPublisher:WILEY