Final Exam Flashcards
What is the equation for formal charge?
of valence electrons - (# of nonbonding electrons + # of bonds)
How do you determine how much negative charge is on each atom in a resonance form?
Add up each charge then divide by the number of atoms
How do you determine what the bond order is in a resonance form?
Add up the number of bonds then divide by number of atoms
What are the rules for bond length in order of importance?
- Bond length decreases across a period
- Bond length decreases with higher bond order
- Bond length increases as you move down a group
-2 electron groups
- 2 bonding groups
- 0 lone pairs
Electron Geometry: Linear
Molecular Geometry: Linear
Bond Angle: 180
3 electron groups
- 3 bonding groups
- 0 lone pairs
Electron Geometry: Trigonal Planar
Molecular Geometry: Trigonal Planar
Bond Angle: 120
3 electron groups
- 2 bonding groups
- 1 lone pair
Electron Geometry: Trigonal Planar
Molecular Geometry: Bent
Bond Angle: <120
4 electron groups
- 4 bonding groups
- 0 lone pairs
Electron Geometry: Tetrahedral
Molecular Geometry: Tetrahedral
Bond Angle: 109.5
What is a Bronsted Base?
Proton Acceptor
What is a Bronsted Acid?
Proton Donator
What are the rules determining acid strength of a molecule?
- Acid strength increases down a group
- Acid strength increases across a period
- A positive charge increases acid strength
- The more halogens, the stronger the acid
- Substituents at remote locations are stronger acids
What are the reagents, Markovnikov addition, and stereochemistry?
What are the reagents, Markovnikov addition, and stereochemistry?
What are the reagents, Markovnikov addition, and stereochemistry?
What are the reagents, Markovnikov addition, and stereochemistry?
What is the product’s sterochemsitry?
What is the product’s sterochemsitry?
What is the product’s regiochemistry?
What are the reagents and product?
What are the reagents and product?
What is an enantiomer?
Non-superimposable mirror image / all chiral centers change
What is a diastereomer?
Some chiral centers change, but not all
What is the stereochemistry of an SN2 reaction?
Inversion of stereochemistry
What reaction will occur if you have a primary substrate?
Most likely SN2, unless there is strong, bulky base then E2
How do you determine between reactions with a secondary substrate?
-Charged nucleophile/base = SN2, E2
-Neutral nucleophile/base = SN1, E1
What reaction does a polar protic solvent favor?
Tend to favor E2
What reaction does an a polar aprotic solvent favor?
Tend to favor SN2
What is a Simmons Smith Reaction?
-ends with a 3 membered ring
-retention of configuration
-form triangle where double bond was
What is the Grignard reaction?
- Break C-O double bond
- Add R group
- Protonate O to get alcohol
What happens if you react an Alcohol with an H-X acid?
Create an alkyl halide
What happens in an oxidation of an alcohol? What are the reagents?
-gain a C-O bond
-lose alpha hydrogen
-Reagents: Na2CrO7, CrO3, H2SO4/H2O
What happens in a Williamson Ether Synthesis reaction?
-Deprotanate OH
-Attachment of new solvent group to O
What happens in an alkoxymercuration-reduction reaction?
-Form HgOAc ion
-Add Solvent group to more substituted group
-Reduce HgOAc to H
What happens in a dehydration of alcohols?
-Removal of OH group by acid
-Form double bond
What happens with reaction of ethers and acid?
-Break ether
-create alkyl halide
What does mCPBA, H2O2, or MMPP do?
Break double bond and add epoxide to it
What happens when you react a halohydrin with a base?
-Synthesis of epoxide by base deprotanating OH group and O then attacks carbon with halogen
What happens when you react epoxide in basic conditions?
-Nucleophile attacks least sterically hindered carbon
-break epoxide & create alcohol
-anti-addition
What happens when you react epoxide in acidic conditions?
-Break epoxide & create alcohol
-add nucleophile to more substituted carbon
What is a glycol? How do you synthesize glycols with epoxides?
Glycol: hydroxy groups (OH) on adjacent carbons
-epoxide ring opening under acidic/basic conditions = trans glycols
How do you synthesize glycols with metals?
OsO4 creates cis glycols
