ALKENES AND ALKYNES (Double and Triple Bonds)

Today we learned about double & triple bonds, trans & cis butene, and multipliers!

• Carbon can form double & triple bonds with carbon atoms
• When multiple bonds form, fewer hydrogens are attached to the carbon atom
• Naming rules are almost the same as Alkanes (single bonds) but instead we use 2 different endings
• For DOUBLE BONDS (Alkenes) it ends with -ene (i.e Butene)
• For TRIPLE BONDS (Alkynes) it ends with -yne (i.e Heptyne)
• *The position of the double/triple bonds always has the lowest number and is put infront of the parent chain

Let's try a few examples shall we?

NAME THE FOLLOWING COMPOUNDS:

Double Bonds -ene

1. First determine the longest carbon chain. The longest Carbon chain here is 6, therefore we use the stem name -HEX

2. Next, you see a double bond represented by 2 lines (circled in red). Then you know our ending has to end with -ene. So it is 1 Hexene

3. Since you've found your parent chain (1 Hexene), determine the side chains. On #3 and #4 you see a 2 carbon group therefore it is 3,4 diethyl

4. So your answer is 3,4 diethyl hexene

Triple Bond: -yne

MULTIPLE DOUBLE BONDS:

• More than 1 double bond can exist in a molecule
• Use the same multipliers inside the parent chain

We also learned about TRANS & CIS BUTENE!

• If 2 adjacent carbons are bonded by a DOUBLE BOND and have side chains on them 2 possible compounds are possible!
• CIS and TRANS:

Lets try 1 more hard one shall we? Name this compound!

Answer:  4 ethyl, 4,5 dimethyl1 heptene

-Post by Ren