Consider a Newman projection of 2-methylbutane shown. Calculate the energy from the strain present in this conformation. CH3 H3C. H Interaction Type gauche CH₁-H gauche CH3-CH3 eclipsed CH3-H eclipsed CH3-CH3 H H CH3 Strain Energy (kcal/mol) 0.0 0.7 3.3 5.6

2. Our knowledge of chair conformations allows us to use them to determine a great deal about a reaction's mechanism. In particular, using a t-butyl group to 'fix' a cyclohexane in a single conformation can help us learn about the spatial requirements and energetics of a reaction. Consider the following two reaction products: a. NO NID ALOH 1) NaCN 2) H+ 1) NaBH4 2) H3O+ OH Group -H -CN -OH A Value (kcal/mol) Defined as 0 0.2 kcal/mol 1.0 kcal/mol Draw the most stable chair conformation for each of the two products. b. Based on the A values in the table above, do the two products have the most stable conformation at the new stereocenter?

Calculate strain energy for the conformed pictured below, using strain energy increments from the table.

Complete the question on paper and snap a photo and upload it as your submission in jpg or pdf format. CI IO H OH a. Generate a Newman projection of the molecule shown above. The red arrow indicated the direction from which your eyes are looking at the molecule. b. Also draw a Newman projection of a conformation that is less stable than the one that you have draw in a. There may be more than one correct option to generate a less stable Newman projection - you need only generate one. You can rotate around the C-C single bond to go between eclipsed and/or staggered conformations. c. Describe why the conformation in b. is less stable than a (name the interactions that make the conformation less stable). Point out where on your structure those interactions are (circling is fine).

Which is the most stable conformation of the following given trisubsituted cyclohexane?

In kcal/mol