Chapter 4.13, Problem 30P

4. (a) Draw a skeletal (line-bond) structure for 3,4-dimethylhexane. (b) Draw a sawhorse representation of any staggered conformation of this molecule looking down the carbon-3 to carbon-4 bond. (c) Draw a Newman projection looking down the carbon-3 to carbon-4 bond of the same conformation that you drew as a sawhorse representation.

There are three distinct chair conformations for cyclohexylcyclohexane. (a) Draw all three and (b) determine which one is the most stable. Cyclohexylcyclohexane

draw the most stable conformation of (a) ethylcyclohexane (b) 3-isopropyl-1,1-dimethylcyclohexane

Consider 1-bromopropane,  CH3CH2CH2Br. (a) Draw a Newman projection for the conformation in which ­ CH3 and -Br are anti (dihedral angle 180°). (b) Draw Newman projections for the conformations in which - CH3 and -Br are gauche (dihedral angles 60° and 300°). (c) Which of these is the lowest energy conformation? (d) Which of these conformations, if any, are related by reflection?

(c)Conformational isomer is the different spatial arrangement of the atoms that resulted from rotation about a single bond. (i) Differentiate anti conformers and gauche conformers (ii) Using a newman projection, draw the anti conformer and gauche conformers of 3,3-dimethylheptane (viewed along the C3-C4 bond)

Take a look at the butane conformers below. Identify: (a)Which is an anti conformation in Newman? (b)Which is a Gauche conformation? (c)Which is the more stable Sawhorse conformer? (d)Which has the same potential energy/strain with ALS?

Draw each of the following. (a) Draw a Newman Projection of the following molecule, looking down the C3-C4 bond. Draw C3 in the front. CI Br H (b) Draw a Newman Projection of the most stable and the least stable conformation of the following molecule. Label each H H. CI H CI H

Draw each compound in its most stable conformation(s). Then draw it in its most symmetric conformation, and determine whether it is chiral.(a) 2-methylbutane

Consider the attached tricyclic structure B. (a) Label each substituent on the rings as axial or equatorial. (b) Draw B using chair conformations for each sixmembered ring. (c) Label the atoms on the ring fusions (the carbons that join each set of two rings together) as cis or trans to each other.