Cycloalkanes

CYCLOALKANES: Hydrocarbon chains which connect in a head-to-tall"circle"are called CYCLC HYDROCARBONS or CYCLOALKANES.

molecules.
 * **Cycloalkanes** (also called **naphthenes**, especially if from petroleum sources) are types of alkanes which have one or more rings of carbon atoms in the chemical structure of their
 * Cycloalkanes** have one or more rings of carbon atoms. The simplest examples of this class consist of a single, unsubstituted carbon ring, and these form a homologous series similar to the unbranched alkanes. The IUPAC names of the first five members of this series are given in the following table. The last (yellow shaded) column gives the general formula for a cycloalkane of any size. If a simple unbranched alkane is converted to a cycloalkane two hydrogen atoms, one from each end of the chain, must be lost. Hence the general formula for a cycloalkane composed of **n** carbons is **CnH2n**.
 * __1. Parent Chain__**
 * 1) Use the cycloalkane as the parent chain if it has a greater number of carbons than any alkylsubstituent.
 * 2) If an alkyl chain off the cycloalkane has a greater number of carbons, then use the alkyl chain as the parent and the cycloalkane as a cycloalkyl-substituent.


 * __2. Numbering the Cycloalkane__**
 * 1) When numbering the carbons of a cycloalkane, start with a substituted carbon so that thesubstituted carbons have the lowest numbers (sum).


 * 1) When two or more different substituents are present, number according to alphabetical order.


 * __3. Halogen Substituents__**
 * 1) Halogen substituents are treated exactly like alkyl groups



This is known as the "chair" form of cyclohexane - from its shape which vaguely resembles a chair.

Examples of Simple Cycloalkanes
||~  ||~   ||~   ||~   ||~   ||~   ||~   || Formula** || C3H6 || C4H8 || C5H10 || C6H12 || C7H14 || CnH2n || Formula** || ||  ||  ||  ||  || (CH2)n || Formula** || ||  ||  ||  ||  ||  ||
 * **Molecular
 * **Structural
 * **Line

|| **Note:** This molecule is constantly changing, with the atom on the left which is currently pointing down flipping up, and the one on the right flipping down. During the process, another (slightly less stable) form of cyclohexane is formed known as the "boat" form. In this arrangement, both of these atoms are either pointing up or down at the same time. ||
 * || 

( From :[])