Alkynes and Alkenes

In Chem class, we learned about double & triple bonds, trans & cis butene

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

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



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:








Can you name this compound?









Answer: 4 ethyl, 4,5 dimethyl1 heptene