Identifying Cyclic Alkanes: C6H12 - C9H18 - C10H20

[312213]

Homework Statement

Name each of the following cyclic alkanes, and indicate the formula of the compound.
http://img230.imageshack.us/img230/1042/organicnaming.jpg

Homework Equations

The Attempt at a Solution

a. The rectangle has four corners so four carbon for butane. The branch off has two carbons so eth-. Numbering the branch C as 1, the naming is 1-ethylcyclobutane with C₆H₁₂ because each corner is 1 C plus the C written and the H comes from subtracting 4 with the number of bonds connected to each of the C. Is this correct?

b. The pentagon has five corners so five corner for pentane. The branch off is prop- and meth-. Naming starts with alphabetical order so meth- first so the prop- is three. 1-methyl-3-propylcyclopentane. Logic from a., C₉H₁₈. Is this correct?

c. Hexane from six corners. Dimethyl and ethyl here. Is this named 1-ethyl-2,6-dimethylcyclohexane or 2-ethyl-1,3-dimethylcyclohexane? C₁₀H₂₀.

If there is a mistake, which part?

 

[Mtnbiker]

Homework Statement

Name each of the following cyclic alkanes, and indicate the formula of the compound.
http://img230.imageshack.us/img230/1042/organicnaming.jpg

Homework Equations

The Attempt at a Solution

a. The rectangle has four corners so four carbon for butane. The branch off has two carbons so eth-. Numbering the branch C as 1, the naming is 1-ethylcyclobutane with C₆H₁₂ because each corner is 1 C plus the C written and the H comes from subtracting 4 with the number of bonds connected to each of the C. Is this correct?

b. The pentagon has five corners so five corner for pentane. The branch off is prop- and meth-. Naming starts with alphabetical order so meth- first so the prop- is three. 1-methyl-3-propylcyclopentane. Logic from a., C₉H₁₈. Is this correct?

c. Hexane from six corners. Dimethyl and ethyl here. Is this named 1-ethyl-2,6-dimethylcyclohexane or 2-ethyl-1,3-dimethylcyclohexane? C₁₀H₂₀.

If there is a mistake, which part?

A is just ethylcyclobutane. There is no need to number the substituent, since a cycloalkane with 1 substituent will always have it at the #1 carbon. You had the formula right.

B is correct.

C is 2-ethyl-1,3-dimethylcyclohexane (you number so as to give your substituents the lowest number possible, in the absence of priority substituents such as OH). Formula is correct.