Alicyclics and aromatics

We learned about alicyclics and aromatics

Carbon chains can form 2 types of closed loops
Alicyclics are loops usually made with single bonds
If the parent chain is a loop standard naming rules apply with one addition: "cyclo" is added in front of the parent chain
There are 3 different ways to draw organic compounds:

• Complete structural diagram
• Condensed structural diagram
• Line Diagram

Numbering can start anywhere and go clockwise or counterclockwise on the loop but side chain numbers MUST be the lowest possible!


CONDENSED STRUCTURAL DIAGRAMS

A condensed structural diagram always shows carbons and hydrogens in it
loops can also be side chains
same rules apply but the side chain is given a cyclo- prefix




NAMING COMPOUNDS


You see 2 lines connecting CH2 and C, so you know this organic compound forms a double bond and you must use the ending -ene
You count the longest carbon chain to be 5 so we use -pent
-pent + -ene = pentene and this bond occurs at 1 so: 1 pentene
we see a loop on #3 of the carbon chain so we must use to prefix -CYCLO and there are 3 of the CH's on it so we use propyl and carbon and hydrogen on #2
#2: 2 methyl
#3: 3 cyclopropyl
2 methyl 3 cyclopropyl 1 pentene


AROMATICS:

Benzene (C6H6) is a cyclic hydrocarbon with unique bonds between the carbon atoms
Structurally it can be drawn with alternating double bonds
Careful analysis shows that all 6 C-C bonds are identical and really represent 1.5 bond
This is due to electron resonance for electrons are free to move all around the ring


AROMATIC NOMENCLATURE:

A benzene molecule is given a special diagram to show its unique bond structure


A benzene can be a parent chain or a side chain
As a side chain it is given the name phenyl

Draw line diagrams
a) 1, 4 diethyl 2 methyl Benzene
b) 1,3,5 triethyl 2,4,6 tripropyl benzene