Q.4-27 - Organic Chemistry (Mcmurry)

Question

Draw the five cycloalkanes with the formula ${\mathbf{C}}_{\mathbf{5}}{\mathbf{H}}_{\mathbf{10}}$.

Step-by-Step Solution

Answer

The five cycloalkanes with chemical formula ${\mathrm{C}}_5{\mathrm{H}}_{10}$:

• Cyclopentane
• Methylcyclobutane
• Ethylcyclopropane
• $1,1-\dim ethylcyclopropane$
  
• $cis-1,2-\dim ethylcyclopropane$
  

Cis and Trans configuration

Cis configuration is when two groups are on the same face of the ring and trans configuration is when the groups are on opposite faces. Both isomers are stable and neither can be converted into the other without breaking and reforming chemical bonds.

Rules for the naming of compound

• Find the parent

Count the number of carbon atoms in the ring and the number in the largest substituent whichever has the highest carbon atom will be considered as the parent. If the number of carbon atoms in the ring is equal to the number in the substituent in that case ring is taken as the parent.

.

• Number the substituents, and write the name.

For an alkyl- or halo-substituted cycloalkane, choose a point of attachment as carbon 1 and number the substituents on the ring so that the second substituent has as low a number as possible. Same procedure for third or fourth substituent so has the low number as much as possible, until a point of difference is found.

 

• When two or more different alkyl groups are present that could potentially take the same numbers, number them by alphabetical priority, ignoring numerical prefixes such as di- and tri-.

 

• If halogens are present, treat them just like alkyl groups.

.

Name and structure of five structures possible

The five cycloalkanes with chemical formula 

                                                              Cyclopentane

                    Methylcyclobutane

                                                  Ethylcyclopropane