2018-4-6 · Step 6 (a) Branch name(s) added as a prefix to the name of the stem. More than 1 branch is present, go to step 6 (b) Step 6 (b) If two or more identical branches are present: (i) Use the prefixes di, tri, tetra, etc before the branch name. Two methyl branches dimethyl (ii) Indicate the location of the stem carbon atoms to which each branch is attached by writing the numbers in ascending order ...