Hey, how's it going in the world of alkanes? 
That's right, the longest chain has seven carbons which is heptane so that is the parent name.
CH3
1 2 3| 4 5 6 7
CH3–CH2–C–CH2–CH–CH2–CH3
| |
CH2 CH3
|
CH3
Now which end to start numbering from, since there is a group attached to third carbon from either end, we break the tie by seeing which end a second group is closest to, which is the left end (there is a methyl group and an ethyl group attached to the third carbon from that end). The other methyl group is on carbon 5. So the alkane is 3-ethyl-3,5-dimethylheptane.
BTW there is another chain that has seven carbons:
CH3
3| 4 5 6 7
CH3–CH2�?/FONT>C–CH2–CH–CH2–CH3
| |
2 CH2 CH3
|
1 CH3
But this gives the same result, 3-ethyl-3,5-dimethylheptane, so it makes no difference in this case.
For the group names, just memorize the common ones and that'll make things a lot easier!
––CH3 = methyl \
| These are the "big two" that you see most often.
––CH2�?/FONT>CH3 = ethyl /
––CH2�?/FONT>CH2�?/FONT>CH3 = propyl
CH3
|
––CH–CH3 = isopropyl
etc.
Steve
Free Forum Hosting
Important Announcement
Prev Message
