Rules for naming
Chem 108, 2006
I. General rules
a. Name parent chain first
b. Locate and name substituents so that substituents have lowest numbers possible.
c. Substituent names end in –yl
d. Multiple identical substituents should have the prefixes:
2 – di
3 – tri
4 – tetra
And remember to include an “address” for each substituent.
e. If substituent numbers are the same in both directions, number in alphabetical order.
f. Write out name with substituents first and then parent chain name,
g. Put commas between numbers and dashes between numbers and words.
II. cyclic molecules
a. put a cyclo- in front of parent chain name.
b. Alkenes get the numbers 1 and 2 in cyclic molecules.
c. Alcohols are assumed to have the number 1 on a cyclic molecule (you don’t need to include the 1)
III. Functional groups
a. Functional groups (such as alkenes, alkynes and alcohols) are named by changing the suffix of the parent chain name.
b. Give the functional group in the parent chain name the lowest number possible.
c. Halogen substituent names are:
i. Fluoro- for fluorine
ii. Chloro- for chlorine
iii. Bromo- for bromine
iv. Iodo- for iodine
d. to name an ether, name the group on either side of the oxygen followed by “ether”
IV. Cis/tran isomers
a. Write cis or trans in front of the alkene or cycloalkane name whenever cis/trans isomers are possible.
b. Cis substituents are on the same side of the molecule and trans are on opposite sides.
V. Benzene
a. Whenever you have a benzenze, make it the parent.
b. Number substituents as you would with other molecules, followed by benzene.
c. If the benzene has an alcohol on it, name it phenol.
Date: 2/29/06
Contact: rajameton@lcsc.edu