Chapter 4 Flashcards
What is the prefix for 1 carbon?
meth-
What is the prefix for 2 carbon?
eth-
What is the prefix for 3 carbon?
prop-
What is the prefix for 4 carbon?
but-
What is the prefix for 5 carbon?
pent-
What is the prefix for 6 carbon?
hex-
What is the prefix for 7 carbon?
hept-
What is the prefix for 8 carbon?
oct-
What is the prefix for 9 carbon?
non-
What is the prefix for 10 carbon?
dec-
Describe the three-part system of IUPAC Nomenclature.
Prefix-Parent-Suffix
Prefix tells you the location and names of substituents
Parent tells you the number of carbons in your main chain
Suffix tells you the type of functional group
How do you choose the main chain? If that system gives two options, how do you choose?
The longest continuous carbon chain is the main chain
If there is a tie, choose the one with the greatest number of substituents
How do you number substituents? What happens when there is more than one at a single carbon? What happens if you get two options?
Try to get the smallest numbers possible
If there are two or more things at a number, they count as two
If each way of counting results in the same numbers, use the alphabet
How do you order substituents? What happens if you have more than one of the same?
When you have substituents with different names, go alphabetical
Don’t repeat a substituent, instead use #,#-di[substituent] (Di, Tri, or tetra)
When do you use hyphens? (one regular and one weird way)
Separate numbers and words with hyphens
Ter- and Sec-butyl are the only ones that are hyphenated
When do you use commas?
Separate numbers by commas
What is the suffix for alkyl groups?
-yl
Alkyl Groups-> When do you use the iso prefix?
All carbons except for one form a continuous chain, or you could look at it like a carbon with two methyl groups
Alkyl Groups-> When do you use the neo prefix?
All carbons except for two form a continuous chain, or you could look at it like a carbon with three methyl groups
Alkyl Groups-> When do you use the sec or s prefix?
A functional group is bonded to a secondary carbon (secondary carbons are bonded to two other carbons)
Alkyl Groups-> When do you use the tert or t prefix?
A functional group is bonded to a tertiary carbon (tertiary carbons are bonded to three other carbons)
What is the suffix for alkanes?
-ane
Describe the two-name system for a carbon attached to a halogen
These have two names, an alkyl halide version and a haloalkane version
What prefix would an attached F give?
Fluoro-
What prefix would an attached Cl give?
Chloro-
What prefix would an attached Br give?
Bromo
What prefix would an attached I give?
Iodo
How does priority work with halogens?
They do not get any special priority
What is the suffix for alcohols?
-ol
How do you choose the main chain and numbering with alcohols?
Select the largest carbon chain that includes the carbon attached to the OH
Start numbering from the end that is closer to the OH
How does priority work with alcohols?
OH gets priority over double and triple bonds (numbering and suffix)
What is the prefix of cycloalkanes?
Cyclo-
How do you name when there are two rings?
Suffix is the largest ring
Name like a alkyl group
When would you not name a cycloalkane in the regular way?
If the substituent has a larger chain than a ring, the ring is the substituent
(Remember not to number the carbons that are part of the ring)
What is the suffix for alkenes?
-Ene
How do you identify the main chain in alkenes?
Select the longest chain that contains the C=C
How do you number with a double bond?
Use the smaller number of C=C to indicate its location
Numbering must give priority to the double bond
Numbers that you are giving to the double bond must be consecutive
What is the suffix for alkynes?
-Yne
How do you identify the main chain in alkynes?
Select the longest chain that has the triple bond (same as for alkenes)
How do you number with a triple bond?
Triple bond gets priority as a substituent (unless there is a OH)
Use the smaller number of C≡C to indicate its location
How do you name with cis/trans?
Whenever there is a possibility of your compound being a cis/trans isomer, you have to add the prefix cis- or trans-
What is the suffix for a compound containing both a triple and double bond?
-yne
How do you number a compound containing both a triple and double bond? What happens if you have two options?
Number in the direction that produces a name containing lower numbers
Neither bond gets priority over the other
If you have the same numbers both ways, the double bond gets the smaller #
Describe a basic staggered conformation
The substituents are completely out of line
Describe a basic anti conformation
The bulkiest groups are farthest apart
Describe a basic gauche conformation
The bulkiest groups are closest together
Describe a basic eclipse conformation
The substituents are directly behind each other
In a-cyclic compounds, which has higher energy, a staggered or eclipse conformation? Higher stability?
Staggered is lower in energy and more stable than eclipse, because the bonding electrons are farthest apart
In a-cyclic compounds, which has higher energy, a gauche or anti conformation? Higher stability?
Anti is lower in energy and more stable than eclipse, because the bonding electrons are farthest apart
Name the four arrangements of cyclohexane
Chair, Half-Chair, Boat, Twist Boat
How does cis/trans isomers work with cyclohexane ?
Cis is both pointing in the same direction (up or down)
Trans is pointing in different directions
Describe axial and equatorial positions in cyclohexane
Axial positions are vertical
Can start from headrest (pointing up) or footrest (down)
Alternate pointing up and down
The other ones are equatorial
Order the four arrangements of cyclohexane from low energy/most stable to high energy/least stable. Say why.
The chair has all staggered conformations
The twist-boat has a tiny amount of 1,4-flagpole interactions
The boat has some eclipsed conformations, no angle strain, and some 1,4-flagpole interactions
The half-chair has some eclipse and some angle strain
Which position is more stable, equatorial or axial?
The equatorial position is more stable
The bulkiest one should be in the equatorial, if you can only have one
Describe one of the few reactions alkanes undergo.
they will react with oxygen in the presence of heat (triangle over the arrow) to form carbon dioxide and water
You need heat, and there is heat released (the heat of combustion)
Relate the heat of combustion and stablity
More heat-> less stable
When the angles of the carbons are not what they would like to be, it is less stable
How do you synthesize alkanes from alkenes or alkynes?
Add hydrogen (more will be needed for alkynes) and use a metal catalyst such as Pt, Pd, Ni, Ru
What is syn addition?
When you add D2 to a compound such as a cycloalkane, they are always added on the same side
What is the basic formula for the number of carbons and hydrogens for alkanes?
C=n
H=2n+2
What is the basic formula for the number of carbons and hydrogens for alkenes?
C=n
H=2n
What is the basic formula for the number of carbons and hydrogens for alkynes?
C=n
C=2n-2
What is the basic formula for the number of carbons and hydrogens for cycloalkanes?
C=n
H=2n
How do you calculate an index of hydrogen deficinecy (IHD)?
(# of H atoms of corresponding acyclic alkane - # of H atoms of your molecule) /2
Corresponding=having the same number of carbons
What is the IHD of all cycloalkanes?
1
What is the IHD of all double bonds?
1
What is the IHD of all triple bonds?
2
If you undergo catatylic hydrogenation and still have an IHD, what must be present in the compound? Why?
A ring. If you have a ring, it will not unfold with catalytic hydrogenation, only 2x/3x bonds change.
How can you match a relative energy diagram to a certain bond rotation?
Use the number of possible energy levels (more when a different substituent is added)
