Organic Chemistry Flashcards
If an alcohol is the second highest priority in a compound, what name root will that compound include?
hydroxy-
If a compound contains an alcohol as its highest priority substituent, what would the name of it end in?
-ol (ex. ethanol)
If a compound has two alcohols on the same carbon, and those alcohols are the highest substituent, what would the name of the compound include? What type of alcohol would it be?
-diol
and it would be a geminal diol
If a compound has two alcohols on adjacent carbons, and those alcohols are the highest substituent, what would the name of the compound include? What type of alcohol would it be?
-diol
and it would be a vicinal diol (same VICINITY as each other)
If a compound contains an aldehyde as its highest priority substituent, what would its name end in?
-al (ex. ethanal)
If a compound contains a ketone as its highest priority substituent, what would its name end in?
-one (ex. acetone)
What is the name for the carbon that is two away from the carbonyl carbon?
The beta carbon
If a compound contains an aldehyde or ketone but they aren’t the highest priority substituent, what would the name include to indicate these functional groups?
oxo-
If a compound contains a carboxylic acid, what will the name end with?
-oic acids (ex. ethanoic acid)
What is the longest carbon chain in formic, acetic, and propionic acid?
Formic- 1 carbon
Acetic- 2 carbons
Propionic- 3 carbons
If a compound contains an ester as its highest priority substituent, what will the name end with?
-oate (ex. ethyl propanoate)
How are amides named?
By adding “amide” to the end of the name
How are anhydrides named?
By adding “anhydride” to the end of the name
What is the order of priority of functional groups?
- Carboxylic Acid (Highest Oxidation State)
- Anhydride
- Ester
- Amide
- Aldehyde
- Ketone
- Alcohol
- Alkene/Alkyne
- Alkane (Lowest Oxidation State)
If two compounds have the same molecular formula but different connectivity what type of isomers are they?
Structural (Constitutional) Isomers
ex. hexane vs. 2 methyl pentane
What physical and chemical properties do constitutional isomers share?
None
If two compounds have the same molecular formula and the same connectivity what broad group of isomers do they fall under?
Stereoisomers
If two compounds are the exact same but only differ in their rotation around sigma bonds, what type of isomers are they?
Conformational Isomers
ex. a chair flip
In a Newman projection when the two highest priority substituents line up in the same plane, what conformation is this called?
Totally Eclipsed
What are the interactions that occur between groups in a Newman projections that have large sizes?
Gauche Interactions
For a conformational isomer in a Newman projection, which conformation is the most energetically favorable?
Staggered Anti
For a conformational isomer in a Newman projection, which conformation is the least energetically favorable?
Eclipsed Syn
What is the difference between angle strain and torsional strain within a ring molecule?
Angle Strain- bond angles are forced to deviate from their ideal angle
Torsional Strain- occurs when cyclic molecules are forced into eclipsed or gauche conformations
What is the most stable conformation of cyclohexane?
Chair Conformation
What is the least stable conformation of cyclohexane?
Boat Conformation
In a chair flip what happens to the atoms that were axial and pointing out of the page?
These atoms will become equatorial but will still point out of the page
Is it more stable for a large substituent on a ring to be in the axial or equatorial position?
equatorial
Two compounds have the same molecular formula, same connectivity, but differ in their arrangement in space and cannot be interconverted by breaking some of their bonds. What type of isomers are these compounds?
Configurational Isomers
ex. R vs. S
How would someone be able to differentiate between two enantiomers?
They rotate plane polarized light to equal but opposite angles
What is the level to which a molecule (usually an enantiomer) rotates plane polarized light called?
Optical Activity
What is the equation for the specific rotation of light that an enantiomer causes?
angle = observed rotation/ c x l
Where:
c = concentration
l = path length in dm
If a solution has equal parts of an R and S enantiomer it is said to be what?
A Racemic Mixture
If two compounds differ at one chiral center but the same at another, what type of configurational isomers are they?
Diasteriomers
If a compound has two chiral centers that are the opposite absolute configuration but also has a plane of symmetry, what type of compound is it?
A Meso compound
What molecules take the highest priority when trying to determine absolute configuration?
The substituents with the highest atomic number
In a Fischer projection are the substituents to the side coming out of or going into the page?
They are coming out of the page
thus if H is on the side the absolute configuration that is found must be reversed
What do the quantum numbers tell us about specific electrons?
Their most likely location within an atom
How many pi and sigma bonds are in a double bond?
Sigma- 1
Pi- 1
How many pi and sigma bonds are in a triple bond?
Sigma- 1
Pi- 2
What is stronger, a singular sigma bond or a singular pi bond?
A singular sigma bond
which is why pi bonds are often broken in reactions
How much S character does a SP3 orbital have?
25%
Which is a stronger acid, Alkane or Alkene?
Alkene
Which is a stronger acid, H2 or Alkene?
H2
Which is a stronger acid, Alkyne or Amine?
Alkyne
Which is a stronger acid, Ketone or an Ester?
Ketone
Which is a stronger acid, Alcohol or a Water molecule?
Water
Which is a stronger acid, Alcohol or a Ester?
Alcohol
As a molecule becomes more and more positive, what happens to the acidity?
Acidity increases with charge
ex. NH3 < NH4+
As the atom to which hydrogens are bound to increases in atomic radius, what happens to the acidity?
Acidity increases with increases atomic radius of bound atom
ex. HF < HI
If one atom has a more stable conjugate base than another due to resonance stabilization, which atom has a higher acidity?
Acidity increases as the stabilization of the conjugate base increases
Why does a molecule of CH2IOH have a lower acidity than CH2FOH?
Because F has a higher inductive effect on the conjugate base than does I
As acid strength increases, what happens to nucleophilicity?
It decreases
What makes a good leaving group?
The weaker basicity that a leaving group has the better it is
What type of reactant has a high affinity for electrons?
An Oxidizing agent
because it wants to take H+ from other molecules
Why are transition metals found in many reducing and oxidizing agents?
Because they have multiple oxidation states that allows them to hold many H+ and then give them to the compound they are reacting with
What oxidizing agents are thought of as weak?
- PCC
What oxidizing agents are thought of as strong?
- CrO3/Pryindine
- H2CrO4
- KMnO4
- O3
- H2O2 (mCPBA)
What are some reducing agents?
- LiAlH4
2. NaBH4
Can alcohols hydrogen bond?
Yes
When an alcohol is attached to a aromatic ring what is this compound called?
Phenol
If a compound had multiple alcohol groups added to it, what would happen to the boiling point?
It would increase greatly
If you treat a primary alcohol with a weak oxidizing agent (PCC) what will form?
An Aldehyde
If you treat a secondary alcohol with a weak oxidizing agent (PCC) what will form?
A Ketone
If you treat a primary alcohol with a strong oxidizing agent (Na2Cr2O7) what will form?
A Carboxylic acid
Is the Jones Oxidation a weak or strong oxidizer?
Strong (CrO3)
How can an alcohol be made into a better leaving group?
Through the addition of a mesylate (-SO3CH3) or a tosylate (Aromatic Ring + mesylate)
If two equivalents of an alcohol (or a diol) are reacted to make a protecting group on an aldehyde, what is formed?
An Acetal (2 OR groups on a primary carbon)
If two equivalents of an alcohol (or a diol) are reacted to make a protecting group on a ketone, what is formed?
A Ketal (2 OR groups on a secondary carbon)
How are ketals and acetals removed from protecting a compound?
By adding an aqueous acid
When you oxidize a phenol what do you get?
A Quinone
What is the general structure of a Quinone?
A phenol ring with two carbonyl groups attached
What is the general structure of a Hydroxyquinone?
A Quinone with one or more extra alcohol groups
What is the best solvent for an SN2 reaction to occur?
Polar Aprotic
What is the best solvent for an SN1 reaction to occur?
Polar Protic
If an aldehyde is attached to a ring what name is added to the compound?
-carbaldehyde
In a carbonyl compound, is the carbon electrophilic or nucleophillic?
electrophilic
If you treat an primary alcohol with PCC, what will form?
An Aldehyde
What happens in a nucleophilic attack on a carbonyl?
A nucleophile attacks the carbon of the carbonyl and then the Pi electrons are pushed up onto the oxygen
How are geminal diols formed?
A water molecule (usually catalyzed by acid) attacks a carbonyl
What occurs when one equivalent of an alcohol is left to react with a carbonyl containing compound?
A hemiacetal or hemiketal is formed
What occurs when two equivalents of an alcohol is left to react with a carbonyl containing compound?
A acetal or ketal is formed
What occurs when a nitrogen containing compound reacts with a carbonyl containing compound?
A Imine is formed
What is a cyanohydrin?
A compound that contains a alcohol and a cyanide attached to the same carbon
When a HCN acts as a nucleophile for a carbonyl containing compound, what forms?
A Cyanohydrin
What are the alpha hydrogens on an aldehyde or a ketone containing compound?
The hydrogens that are bonded to the carbon that is adjacent to the carbonyl group
Why are alpha hydrogens more acidic than normal?
The conjugate base is stabilized via resonance contribution from the carbonyl group
How is an enolate formed?
The removal of the proton on a enol (a compound with a double bond adjacent to an alcohol group)
Describe what happens in the Michael addition
A enolate acts as a electrophile and attacks an alpha/beta carbonyl compound
What is the difference between a kinetic and thermodynamic enolate?
Kinetic- formed faster but less stable
Thermodynamic- formed slower but more stable
Describe what happens in an Aldol condensation
An aldehyde or ketone acts as both a electrophile (in its keto form) and as a nucleophile (in its enolate form) to attack itself and form a new carbon-carbon bond
What is the difference between nucleophilic substitution in carboxylic acids compared to ketones/aldehydes?
Carboxylic acids (and their derivatives) have a leaving group
What is a cyclic amide called?
A Lactam
Describe the process of fischer esterification of a carboxylic acid
The carboxylic acid is protonated (making the carbon more electrophilic) then an alcohol attacks the carbon which then eventually kicks off one of the -OH groups leaving an ester
What are cyclic esters called?
Lactones
When two carboxylic acids condense together what is formed?
An Anhydride
What is a Beta-Keto acid?
A compound that contains two carboxylic acids that are one carbon away from each other
Describe the process of decarboxylation
A Beta-Keto Acid forms intramolecular bonds causing the removal of a CO2 and you are left with a ketone
Describe the structure of soaps
Soaps have deprotonated carboxylic acids with long fatty chains that organize themselves into micelles (acid heads facing outward and hydrocarbon tails facing inward)
What are two common cyclic anhydride compounds?
Phthalic anhydride
and
Succinic anhydride
What is the order of carboxylic acid derivatives in terms of reactivity toward nucleophilic attack?
- Acyl Chlorides
- Anhydrides
- Carboxylic Acids = Esters
- Amides
If a nucleophile (such as NH3) attacks and anhydride what reaction occurs and what are the products?
This reaction is called an anhydride cleavage
Products:
1) A carbonyl group attached to the attacking nucleophile
2) A carboxylic acid
When an alcohol attacks an ester and acts as a nucleophile what reaction occurs and what are the products?
This reaction is called a transesterification
Products:
1) A new ester with the new -OR group
2) A primary alcohol
What isomer of amino acids occurs naturally in the body?
L-isomer
What are two ways of synthesizing amino acids?
Strecker Synthesis
and
Gabriel Synthesis
Describe what happen in the Strecker Synthesis
1) An aldehyde is protonated with a ammonium and then the nitrogen does a nucleophilic attack to form an Imine
2) A nitrile attacks the imine forming an aminonitrile [nitrogen and nitrile present]
3) The aminonitrile is protonated and water then attacks twice as a nucleophile
4) Another ammonia attacks as a nucleophile this creating a compound with a carboxylic acid, nitrogen and and R group that comes from the original aldehyde (An Amino Acid)
Describe what happens in the Gabriel Synthesis
1) Start with Potassium Phthalimide and Diethyl Bromomalonate that combine in an SN2 reaction
2) A base is added to make the SN2 addition of an R-Br group more favorable
3) The dicarboxylic acid is decarboxylated to cleave the primary amine
What does spectroscopy measure?
Measures the energy differences between the possible states of a molecular system by determining the frequencies of different electromagnetic radiation emissions
Which type of spectroscopy measures the molecular vibrations (bond streching, bond bending) by passing infrared light through a substance and measuring the absorbance of different peaks?
Infrared Spectroscopy
A scientist can look at the region on an IR spectroscopy graph and tell exactly what the compound is. What region of the chart is this called?
Fingerprint Region (400-1500 cm-1)
In an IR spectroscopy what is the difference between an alcohol, amine, and a carboxylic acid peak?
The carboxylic acid peak is broad like a beard while the alcohol is a sharper peak and the amine is the sharpest peak
Where do -OH bonds show up on an IR spectroscopy?
3100-3500 cm-1
Where do -NH bonds show up on an IR spectroscopy?
3100-3500 cm-1
Where do carbonyl bonds show up on an IR spectroscopy?
1650-1800 cm-1
Where do -CH bonds from alkanes show up on an IR spectroscopy?
2800-3000 cm-1
Where do -CH bonds from alkenes show up on an IR spectroscopy?
3100-3200 cm-1
Where do -CH bonds from alkynes show up on and IR spectroscopy?
3300 cm-1
What type of spectroscopy uses ultraviolet light that is passed through a sample that has been dissolved in an inert substance?
UV spectroscopy
What is UV spectroscopy best at measuring?
The presence of conjugated systems in a compound
How is nuclear magnetic resonance (NMR) spectroscopy done?
A compound is exposed to a magnetic field and its atomic nuclei will orient in certain ways in response to the magnetic field. Then radiofrequency pulses are sent through the sample allowing for the absorption of certain frequencies by the sample, which is recorded
Why is TMS used in NMR spectroscopy?
TMS is the baseline reference peak that gives a signal at 0 ppm
How does H-NMR tell us about the different types of hydrogen molecules in a sample?
The number of peaks represents the number of different hydrogens
How does H-NMR tell us about the total number of hydrogens in a sample?
The total number of hydrogens would be the sum of all the integration numbers from the different peaks
If a peak representing hydrogens in H-NMR is shifted further to the left, what does this mean about those hydrogens?
These hydrogens are in a more electronegative bond (aldehyde, close to a halogen)
How does H-NMR tell us about the numbers of neighboring hydrogen that a specific hydrogen will have?
The number of peaks minus 1 (n - 1) in a specific band will tell us how many neighboring hydrogens there are
Where do hydrogens on carboxylic acids appear on H-NMR?
10-12 ppm
Where do hydrogens on aldehydes appear on H-NMR?
9-10 ppm
Where do hydrogens on aromatic compounds appear on H-NMR?
6-8.5 ppm
If a compound is found to have only Van Der Waals interactions, what phase in an extraction setup would you most likely find it?
The organic phase
If a compound is found to have hydrogen bonding, what phase in an extraction setup would you most likely find it?
The aqueous phase
If a the organic phase is less dense than the aqueous phase would it be on the top or bottom of the separation funnel?
The top
What is the difference between a regular extraction and a wash?
In an extraction the compound of interest is removed (usually in the aqueous phase)
In a wash the compound of interest is left in the separation funnel
Describe the process of recyrstallization
The product is dissolved in a hot solvent and then as the solvent cools the purified product will crystalize out of the solution due to a decreased solubility
How does a vacuum setup effect a distillation?
It is used to distill compounds with a boiling point over 150 Celsius. This is because the vacuum lowers the vapor pressure and thus lowers the boiling point and allows the desired product to distill at a lower (safer) temperature
What is the difference between a regular distillation and a fractional distillation?
A fractional distillation separates two liquids with very similar boiling points (less than 25 Celsius apart). It does this by increasing the surface area of the condensing tube to allow for maximal time for the higher boiling point liquid to condense back into the flask
What is the difference between the stationary phase and the mobile phase in chromatography?
Stationary Phase- the medium through which the mobile phase will run through. Its properties (polar, charged, etc.,) will determine what is being measured
Mobile Phase- the substances that are being tested and compared
How are thin-layer and paper chromatography similar?
They both use a polar stationary phase
- Thin layer uses silica or alumina
- Paper uses cellulose
Will a non-polar substance travel farther or shorter up the stationary phase in thin-layer and paper chromatography?
It will travel far up because it is not attracted to the polar stationary phase
How is reverse phase chromatography different from thin-layer chromatography?
Reverse phase uses a non-polar stationary phase
How is retardation factor found (Rf)
Rf = distance spot moved / distance solvent front moved
What is the difference between thin-layer chromatography and column chromatography?
In column chromatography, the mobile phase is pulled down through a column (filled with the stationary phase) by gravity
What type of chromatography uses charged substances as the stationary phase in a column setup?
Ion-exchange chromatography
What type of chromatography uses beads with tiny pores to separate out large vs small compounds (done with a column setup)?
Size-exclusion chromatography
In size-exclusion chromatography, would a larger or smaller compound elute first?
A larger compound
What type of chromatography uses a column setup to separate out different proteins?
Affinity Chromatography
How is gas chromatography unique?
The mobile phase is a vaporized gas that travels through a long coil and elutes onto a detector that is read by a computer setup
What type of chromatography uses a liquid that is highly pressurized through the stationary phase and the elutent rate is measured by a computer?
High Performance Liquid Chromatography
What does a high Rf value indicate?
the substance being measured traveled farther in down the stationary phase
