Question

Draw the structure and give the molecular formula for each of the following compounds.

(a) 1-ethyl-3-methylcycloheptane

(b) isobutylcyclohexane

(c) cyclopropylcyclopentane

(d) 3-ethyl-1,1-dimethylcyclohexane

(e) 3-ethyl-2,4-dimethylhexane

(f) 1,1-diethyl-4-(3,3-dimethylbutyl)cyclohexane

Short answer

(a)

(b)

(c)

(d)

(e)

(f)

Step-by-step solution

General concept

Substituted cycloalkanes use the cycloalkane for the base name, with the alkyl groups named as substituents. If there is just one substituent, no numbering is needed. If there are two or more substituents on the ring, the ring carbons are numbered to give the lowest possible numbers for the substituted carbons. The numbering begins with one of the substituted ring carbons and continues in the direction that gives the lowest possible numbers to the other substituents. In the name, the substituents are listed in alphabetical order. When the numbering could begin with either of two substituted ring carbons (as in a disubstituted cycloalkane), begin with the one that has more substituents otherwise, begin with the one that is first alphabetically.

(a)

Cycloalkane is cycloheptane. One methyl group is at third position of the ring and one ethyl group at first position of the ring.

(b)

Cycloalkane is cyclohexane, with attached single iso butyl group

(c)

Cycloalkane is cyclohexane, attached to cyclopropyl ring.

(d)

Cycloalkane is cyclohexane. Two methyl group are at first position of the ring and one ethyl group at third position of the ring.

(e)

Longest carbon chain is of six carbon atoms (hexane), single methyl group is attached at position 2 and 4, and on ethyl group is attached at third position.

(f)

Cycloalkane is cyclohexane, with two ethyl groups at first position and a butyl chain is attached at fourth position containing two methyl groups at the third position of this chain.