When naming, what is the first thing you look for?
a root name, which tells the number of carbons in the chain
The n-alkanes (describe)
normal, unbranched chains
True or False:
It is rare to have a straight chain.
If you are not dealing with a ring, what can you omit?
Groups attached to alkanes are __. How do you name them?
- alkyl groups
- drop the -ane and add -yl
When classifying, what is...?
- primary: C bearing one C
- secondary: C bearing two C
- Tertiary: C bearing three C
What are the rules (6)?
- 1) find the longest chain
- 2) number the chain from the closest one with a branch
- 3) give attached alkyls a name and number
- 4) If more than one alkyl, name alphabetically
- 5) Several methyl groups, use a numerical prefix
- 6) Halogens are named by dropping -ine and adding -o
If you have a branch within a branch and are told to name alphabetically, how would you go about that?
if in parenthesis and is alphabetically before any other alkyl groups, place first
When dealing with cycloalkanes and only one alkyl group is present, what can be done?
omit the Carbon number
When you have multiple groups on a cycloalkane, how would you number the carbons?
the carbon with the most substituents is first and then go around in a way that produces the lowest numbers (lowest sum)
Explain cis and trans.
if there are only two alkyl groups present, it will be possible. Once a third substituent goes on it, cis and trans go out the window
Every C in a ring has what?
an up bond and a down bond
Explain eclipsed in terms of its energy.
high energy because the sigma bonds are eclipsing one another
What is the only ring without strain?
one a six membered ring
Which bonding of atoms in a Newman projection produces the least amount of energy?
- the H-H bond
- no spatial bonds
- if hydrogens aren't banging into each other, what causes strain?
repulsion from electrons (torsional/ eclipsical [same thing])
Angle strain does what.
raise the energy
The only function that is of angle strain and reacts is what?
doesn't get any higher than eclipsed conformation
lowest enery: staggered
When does steric occur?
when two substituents or atoms are demanding the same space
What are the types of rotation?
- gauche (right next to each other)
- anti (opposite; maximum separation)
What type of conformation is the worse case? Best case?
- syn conformation is worst
- anti is best
How can you lock the stable configuration of a molecule?
by putting a bridging atom in
steric strain usually occurs with? There will be __ from atoms and clouds themselves.
It will try to __ and will occupy a more __ more often.
- large groups
- stable occupation
Angle strain is more likely in what?
Strain energy can be __.
Butane has __ and __ when __
- torsional strain
What do cycloalkanes consist of ?
faces and sides
Which ring is the only flat ring we know of, besides benzene?
different connections between atoms
same connections but different three-dimensional geometry