CHM 2210C                Chapter 3               Sample Exam Answers

Part G-R: STEPS IN NAMING AN ALKANE   5 points

A.    FIND THE PARENT HYDROCARBON

a. Find the longest continuous chain of carbon atoms.

b. If two different chains of equal length are present, choose the larger of branch points as the parent.

B.    NUMBER THE ATOMS IN THE MAIN CHAIN

a. Beginning at the end nearer the first branch point, number each carbon atom in the parent chain.

b. If there is branching and equal distance away from both ends of the parent chain, begin numbering at the end nearer the second branch point .

C.    IDENTIFY AND NUMBER THE SUBSTITUENTS.

a. Assign a number to each substitute according to its point of attachment to the parent chain.

b. If there are two substituents on the same carbon, give them both the same number. There must be as many numbers in the name as there are substituents .

D.    WRITE THE NAME AS A SINGLE WORD

a. Use Hyphens to separate the different prefixes, and commas to separate numbers. Cite them in alphabetical order if two or more substituents are present. 

b. If two or more identical substituents are present use one of the multiplier prefixes DI-,TRI-, TETRA-, and so forth.

E.    NAME A COMPLEX SUBSTITUENT AS THOUGH IT WERE ITSELF A COMPOUND

a. First name the complex substituent. Begin numbering the complex substituent at the point of attachment to the main chain, and identify it as a 2 methylpropyl group.