Each of the following descriptions applies to more than one alkane. In each case, draw and name two structures that match the description.
(a) an isopropylheptane
(b) a diethyldecane
(c) a cis-diethylcyclohexane
(d) a trans-dihalocyclopentane
(e) a (2,3-dimethylpentyl)cycloalkane
(f) a bicyclononane
Step 1 </p>
When drawing chemical structures based on a generic chemical name, be sure that you don’t accidentally write the same structure twice. Also, be sure to double-back and name the structure you’ve drawn, to ensure that you haven’t accidentally drawn a structure that no longer corresponds to the generic name you’ve been given. In this particular example, we’re asked to draw and name two specific structures that correspond to each generic name.
Step 2 </p>
First, we are asked to draw and name two structures that match the description of an isopropylheptane.
As it happens, there is only one structure that corresponds to an isopropylheptane. Placing the isopropyl group on any other carbon of the heptane backbone results in either a longer main chain or the disappearance of the isopropyl group (for nomenclature purposes).
Step 3 </p>
Next, we are asked to draw and name two structures that match the description of a diethyldecane.
Both the 3,5 and the 4,5 isomers match the nomenclature rules for a diethyldecane.
Step 4 </p>
The third part of this set asks us to draw and name two structures that match the description of a cis-diethylcyclohexane.
Both the 1,2 and the 1,3 isomers match the nomenclature rules for a cis-diethylcyclohexane.