Concept explainers
Interpretation:
The amount of steric strain in each of the chair conformers of
Concept introduction:
Strain energy: Ring strain is a type of instability that exists when bonds in a molecule form angles that are abnormal. Strain is most commonly discussed for small rings such as cyclopropanes and cyclobutanes, whose internal angles are substantially smaller than the idealized value of approximately 109°.
Angle strain of cyclic molecules: The German chemist Adolf van Baeyer, believing that all cyclic molecules like planner, proposed that the stability of a cycloalkane could be predicated by determining the difference between this ideal bond angle and the bond angle in the planner cycloalkane.
We consider the simple example of the bond angle in cyclopropane are 600 degree repressing a 45.50 degree it deviation from 109.50, it is proved from Baeyer this deviation cause angle strain which decrease respective molecules stability.
The corresponding Bond strain formula shown below
Want to see the full answer?
Check out a sample textbook solutionChapter 3 Solutions
Essential Organic Chemistry, Global Edition
- Use your answers from Problem 2.48 to complete the table showing correlations between cis,trans and axial,equatorial for disubstituted derivatives of cyclohexane. Draw the alternative chair conformations for the cis and trans isomers of 1,2-dimethylcyclohexane, 1,3-dimethylcyclohexane, 1,4-dimethylcyclohexane. (a) Indicate by a label whether each methyl group is axial or equatorial.arrow_forwardmyo-Inositol, one of the isomers of 1,2,3,4,5,6-hexahydroxycyclohexane, acts as a growth factor in both animals and microorganisms. Draw the most stable chair conformation of myo-inositol.arrow_forwardConsider 1-bromo-2-methylpropane and draw the following. (a) The staggered conformation(s) of lowest energy (b) The staggered conformation(s) of highest energyarrow_forward
- Ketones react with alcohols to yield products called acetals. Why does the all-cis isomer of 4-tert-butyl-1,3-cyclohexanediol react readily with acetone and an acid catalyst to form an acetal, but other stereoisomers do not react? In formulating your answer, draw the more stable chair conformations of all four stereoisomers and the product acetal for each one.arrow_forwardcalculate the amount of steric strain in each of the chair conformers of 1,1,3-trimethylcyclohexane. Which conformer predominates at equilibrium?arrow_forward4. 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_forward
- Which of the following is the most stable conformation of cis-1-ethyl-3-isopropylcyclohexane? II II IVarrow_forwardIndicate the position, axial or equatorial, of the substituents in the more stable chair conformation. CH3 Methyl is [A] OH is [B] Isopropyl is [C] Cl is [D] HO` CIarrow_forwardacyclic conformersarrow_forward
- Construct 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_forwardProvide the least stable(highest energy) chair conformation of chlorocyclohexane.arrow_forward13 Draw the molecule trans-1-ethyl-3- isopropylcyclohexane conformation. Which is the overall most-stable conformer? Justify your answer. in its chair and its flipped chairarrow_forward
- Organic ChemistryChemistryISBN:9781305580350Author:William H. Brown, Brent L. Iverson, Eric Anslyn, Christopher S. FootePublisher:Cengage Learning