assign 3-2 - (b) Indicate the types of strain energy...

Info iconThis preview shows pages 1–3. Sign up to view the full content.

View Full Document Right Arrow Icon
Assign 3-2 1. Consider 2-methylpropane. Make a plot of potential energy (PE) vs. # degrees rotation about the C 1 -C 2 bond. Do a full 360 o rotation. Using Newman projection drawings, show the molecule’s conformation at 60 o intervals. 2. Using a Newman projection formulas, draw the most stable and least stable conformations of 2,3-dimethyl butane with respect to rotation about the C 2 -C 3 bond 3. Each C-H, C-H eclipsing interaction in ethane costs about 4 kJ/mol. (a) How many such interactions are present in cyclopropane? (b) The total strain energy in cyclopropane is 115 kJ/mol (38.3 kJ/mol per CH 2 ...thus, total strain energy = 3 x 38.3 kJ/mol = 114.9 kJ/mol). What % of cyclopropane’s total strain energy is due to torsional strain? 4. Compute the total strain energy present in cis -1,2-dimethylcyclopropane 5. (a) Draw a 3D formula of each of the following cycloalkanes.
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Background image of page 2
Background image of page 3
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: (b) Indicate the types of strain energy present in each. If no strain is present, so indicate. Comment of the relative severity of each strain type. a. cyclobutane (most stable shape) b. cyclopentane (most stable shape) c. cyclohexane (chair form) d. cyclohexane (boat form) e. cycloheptane (puckered ring) 6. Draw the most stable chair conformation of each of the following molecules: (a) cis-1-ethyl-2-methylcyclohexane (b) cis-1-t-butyl-4-ethylcyclohexane 7. (a) Draw the two possible chair conformations for each of the following (i.e., the two chair conformations that arise when the molecule undergoes ring inversion). (b) Compute the total strain energy present in each chair conformation. Indicate which conformer is the more stable. (i) trans-1-chloro-3-methylcyclohexane (ii) cis-1-bromo-4-ethylcyclohexane...
View Full Document

This note was uploaded on 04/07/2009 for the course CHE 311 taught by Professor Drake during the Fall '08 term at American International.

Page1 / 3

assign 3-2 - (b) Indicate the types of strain energy...

This preview shows document pages 1 - 3. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online