Organic Chemistry

What is the formula for an Alkane?
CnH2n+2 (they have the max possible number of hydrogen atoms attached to each carbon, only single sigma bonds)
primary carbon atom
1° the carbon is bonded to only one other carbon
secondary carbon
2° carbon is bonded to 2
Tertiary carbon
3° carbon bonded to 3 other carbons
Quaternary carbon
4° carbon bonded to 4 other carbon atoms
Steric Number SN =
= (# of sigma bonds + # of lone pairs of electrons)
What is formal charge?
(Number of Valence Electrons of an Atom) – (Number of actual Electrons around the Atom in dot structure)
Define Oxidation and Reduction

Oxidation – (increase in oxidation state -4 to +4) loss of electon LEO loss of electron is oxidation

 

Reduction – (decrease in oxidation state 0 to -2) gain of electron GER gain of electron is reduction

 

LEO the lion says GER

Bronsted-Lowry Acid
proton donor
Bronsted-Lowry Base
proton acceptor
Lewis Acid
electron pair acceptor
Lewis Base
electron pair donor
9 pre-fix in orgo
non
10 pre-fix in nomenclature
dec
11 prefix in nomenclature
undec
12 prefix in nomenclature
dodec
13 prefix in nomenclature
tridec
14 prefix in nomenclature
tetradec
15 prefix in nomenclature
pentadec
15 prefix in nomenclature
pentadec
16 prefix in nomenclature
hexadec
17 prefix in nomenclature
heptadec
18 prefix in nomenclature
octadec
19 prefix in nomenclature
nonadec
20 prefix in nomenclature
eicos
What if there are 2 or more parent chains or backbones with different numbers of substituents but the same number of carbons in the parent chain you could draw?
According to IUPAC choose the parent chain with the most substituents
formula for cycloalkane
CnH2n
Rules for naming hydrocarbons

I. Find the longest carbon chain and name it.

II. Number the chain to give the substituents the lowest number possible

III. Identify and number the substituents

IV. Arrange the substituents alphabetically

 

First point of difference rule
If you have a hydrocarbon with the same parent chain, you name all substituents, then find the first difference in the numbers after numbering them and choose the lowest one
If first point of difference in #’s fails then…
you go to the alphabet rule
if there is a tie in the # of carbons in a cyclo and a straight chain…
you name the cyclo the alkane and the straight chain the alkyl
How do you figure out how many rings you have?
By IUPAC determine how many cuts you have to make to make a straight chain and no more rings
What is a bridgehead carbon?
Carbons that merge to rings
Formula for naming bicyclo compounds

bicyclo[x.y.z]alkane

 

x=number of carbons in the longest path excluding bridgehead carbons

y=number of carbons in the second longest path excluding bridgehead carbons

z=number of carbons in the shortest path excluding bridgehead carbons(between bridgehead carbons)

Anti-staggered conformation
the ch3s are 180apart, most stable, least potential energy
Gauche-staggered conformation
the methyl groups or ch3s are 60 degrees apart
define chiral
not superimposable on its mirror image. means hand in greek
what is a chiral carbon/center/atom?
usually a sp3 tetrahedral carbon that is bonded to 4 different groups
stereochemistry
study of 3D chemistry
right in latin
rectus, when you move clockwise from largest to smallest atom on a chiral molecule
left in latin
(S) Sinister, counterclockwise when ordering largest to smallest atom in a chiral molecule
Enantionmers

stereoisomers that are non-superimposable mirror images

greek for “opposite”

opposite configurations at all chirality centers

achiral
objects that are superimposable on their mirror image
Specific Rotation

[alpha]=alpha/c*l

 

[alpha]=specific rotation

alpha=observed rotation

c=concentration (g/mL)

l=path length/length of tube (dm)

optical purity or enantiometric excess

%ee=(observed[alpha]/[alpha]of pure enantiomer)*100

 

alpha = optical activity?

diastereomers

stereoisomers that are nonsuperimposable non-mirror images. it has the same atoms, sames bonds, but not mirror image of each other

-opposite configurations at some chirality centers

mesocompound

compound that has 2 or more chirality centers but the whole molecule is achiral. It can be superimposed on its mirror image

The way to spot them is it has 2 chiral centers, but it has a line of symmetry

Sn1 and Sn2 both like polar solvents, but which one likes protic and which one likes non-protic?
Sn1 likes protics and Sn2 likes non-protic because if Sn2 was in protic, the nucleophile would always join H and the reaction would occur
nucleophile

nucleus lover

-region of high electron density

-attracted to nuclei

electrophile

electron lover

-region of low electron density

 

 

Electrons flow from…
regions of high electron density (N) to regions of low electron density (E)
The 5 most important things to understand in Organic Chemistry (Schwartz Rule)

I. Valence electrons (formal charge, oxidation state, dot structures)

II. Knowing how electronegativity effects reactions

III. Understand Acid/Base theory

IV. Redox chemistry

V. nucleophiles/electrophiles

If you have a halogen or an alkyl in your parent chain,…
just go with the lowest number
What is the fastest alkyl halide classification SN1?

methyl;1o;2o;3o

 

tertiary is the most stable so it want to react to get to that point

Solvolysis
your nucleophile is also your solvent
What happens in a Sn1 halide reaction thinking in terms of stereochemistry

inversions ; 50% of the time (if S goes to R)

retention of the same form ; 50% (if S stays S)

In sterochemistry what happens on a Sn2 reaction?
You only get inversion because the halogen is on the other side. It can only attack on one side
Which classifications are most likely to perform Sn2 reaction?

methyl;1o;2o;3o

 

there is more steric hinderance with 3o

What functions only as a nucleophile (strong nucleophile)?
Cl, Br, I, SH, RSH (polarizable – electrons are far from the nucleus)
What functions as a base only?
H, it is not very polarized because it is small
What can function as a strong Nu or strong Base?
RO, or OH
What functions as a weak Nu or weak base?
ROH or H2O
functional groups on opposite sides of the double bond

trans – latin

entgegen (E) – German “across”

functional groups on the same side of the double bond

cis – latin “together”

(z) Zusamen – german for “together”
 

what is another name for ethene?
Ethylene
general alkene formula?
CnH2n alkenes are “unsaturated” they could have 2 more hydrogens
What is the most stable substituted alkene?
mono;disubstituted;trisubstituted;tetrasubstituted
What is another name for ethyne?
acetylene
Triple bonds cause what configuration?
linear, always draw them linear in a diagram
define miscible
soluble in any proportion in water
What happens to the boiling point as the R-chain gets longer in an alcohol? Why?
The boiling point goes up, because the london dispersion forces increase in longer chains.
Methanol properties
miscible, lower boiling point
butanol properties
soluable but not miscible in water, higher boiling point than methanol
what is phenol?
a benzene ring with a hydroxyl group
What happens when you oxidize primary alcohol?

you must have alpha-hydrogens(hydrogens attached to the alpha carbon)

 

If you oxidize a primary alcohol 1 time you will get an aldehyde

 

What is another way to think about oxidizing?
increasing the C to O bonds, this is because O is more electronegative so it grabs those electrons from the C.
What happens when you oxidize a secondary alcohol?
you get a ketone
What happens when you oxidize a tertiary alcohol?

in theory you can’t because you must have alpha hydrogen attached to the alpha carbon.

The result is NR no reaction

What is the “jones reagent”?

Sodium Dichromate (Na2Cr2O7)

Sulfiric Acid (H2SO4)

Water (H2O)

 

this mixes together to form chromic acid which is used to oxidize alcohols

you can also use CrO3/H3O+/acetone

Is dimethyl ether liquid or gas a room temp?
It is a gas, the boiling point is -25it doesn’t have hydrogen bonding in its intermolecular forces
What happens to the boiling points of ethers as the carbon chains increase?
They go up because the dipole dipole moments increase, london dispersion forces
How do you name aldehydes?
add “al” to the alkane
What are some common aldehydes?

formaldehyde – used to store dead things in (really strong smell)

benzaldehyde – (rosy smell)

cinnimaldehyde – (cinnamon smell)

acetaldehyde – (

 

Most basic Ketone, and how do you name ketones?

acetone (german for ketone)

write ketone at the end

or add “one” after the alkane

what is the priority for naming functional groups?
Carboxylic Acids 
Acid Anhydrides 
Esters 
Acyl Halides 
Amides 
Nitriles 
Aldehydes 
Ketones 
Alcohols 
Thiols 
Amines 
Ethers 
Sulphides 
Alkenes 
Alkynes 
Alkyl Halides 
Nitro 
Alkanes 
what is formic acid?
has an H on one side of the carbonyl and OH on the other
what is oxalic acid
two carbonyls attached to each other with two OH’s
How do you name caboxylic acids?

add “oic acid” to the end of the alkane ex: butanoic acid

this will be at the beginning or end of the chain

How do you name an amine?

add amine to the end “cyclohexanamine”

 

if it’s not highest priority, use “amino”

What is aniline?
NH2 connected to a benzene ring
What is conjugation in Ochem?
alternating double and single bonds
What is an allylic carbocation?
A carbocation that can be more stableized through a resonance structure
How do you control a conjugated diene addition reaction?
By temperature, the 1,2 adduct happens faster, therefore at lower temperatures it is kinetically controlled. the 1, 4 happens slower, therefore, with more energy and higher temp it is the product
what is a concerted mechanism?
all the transfers and leaving happens at the same time
what do endo and exo mean in stereochemistry?
you compare the stereochemistry of the substituents. If the other bridge goes down to form a box, look if the OH is in or out of the box
What is the Diels-Alder reaction?
when you merge a dien and a dienophile to make a cyclic or bicyclic compound. When you start with a cis dienophile your products are cis too, when you start with trans your products are trans too
What products are favored in for regiochemistry in diels-alder reactions?

para(subs across 1,4) and ortho(subs by each other 1,2) are favored

 

meta is not favored(1,3)

What is an in-phase molecular orbital?
goes from two atomic orbitals to one molecular orbital and they share electron densities through a covalent bond. It is called “bonding MO” they are lower in energy than anti-bonding MO or out of phase
What is out of phase MO?
two atomic orbitals make 2 MOs and they are called “anti-bonding” they form a node and do not share electron density. So there is a + and a + repelling each other in the middle so they are high energy
what is HOMO?
highest occupied molecular orbital
What is LUMO?
lowest unoccupied molecular orbital
What are the frontier orbitals?
the LUMO and HOMO, the highest energy occupied mo and the next mo up that is unoccupied
What are complementary colors in the light spectrum?
If you combine them you get white light
What happens when you increase the amount of conjugation in a molecule?
You decrease the amount of energy it takes to get to an antibonding MO and it increases the wavelength making it easier and easier to see a visible color
Why does bleach take out the color?
it reacts with the highly conjugated molecule and makes it less conjugated because it stops the sequence. Therefore the molecule doesn’t absorb as high a wavelength so a visible color can’t be seen.
what is toluene?

a benzene ring with a methyl group attached

 

what is benzoic acid?
a benzene ring with a carboxilic acid attached
what is benzaldehyde?

a benzene ring with an aldehyde group

it has the smell of almonds

what if the benzene ring is coming of as a substituent(the straight carbon chain is longer)?
you use “phenyl” it is a phenyl group
What is styrene?
a benzene ring with a monosubstituted alkene
what is anisole?
a benzene ring with and ether
what is acetophenone?
a benzene ring with a ketone
What is xylene?
a benzene ring with 2 methyl groups coming off of it
what is vanillin?
a benzene ring with an aldehyde, alcohol, and ether substituent
what is TNT?
benzene ring with a methyl, and three nitro groups (2,4,6-trinitrotoluene)
a compound is aromatic if…

I. contains a ring of constinuously overlapping p orbitals (planar)

II. has 4n+2 (huckel’s rule) pi electrons in the ring, where n = 0,1,2…or any other positive integer

What do 2 unpaired electrons imply?
instability and very reactive
what does anti-aromatic mean?
a compound that fulfills the first rule but not the second of aromatic compounds
What is an electrophilic aromatic substitution?
you have a electrophile and the double bond acts as a nucleophile. Then it gets deprotinated
Why are the para and ortho formed with with a methoxy group in the benzene ring when you do a electrophile aromatic substitution reaction?
the methoxy group allows it to have 4 reasonance structures rather than just 3 in the ortho and para attack. It has a more stable sigma complex
what is an activator?
and electron donating group with increases electron density in a benzene ring
what is a deactivator?
EWG – electron withdrawing group, decreases electron density in the benzene ring
Why is the meta preferred when there is a nitro group attached to the benzene ring?
because there is a resonance structure in ortho and para that is not stable the N and C are both positive, it is a destablizing reasonance structure
How do you quickly find a meta director?
see if the substituent has a + or partial + charge, then it is meta
What is a stronger activator OH or a methyl group?
OH
What are the steps in the Birch reduction reaction?

1. Na or another donates an electron.

2. the anion picks up a proton H

3. Na donates electrons

4. the anion picks up a proton H

what are the requirements for nucleophilic aromatic substitution?

1. The ring has an electron withdrawing group

2. The ring has a leaving group

3. The leaving group is ortho or para to the EWG

If p orbitals are in the same energy level, they are called?
degenerate orbitals
what is the general rule for determining ionic and covalent bonding in terms of electronegativity differences?

0 = purely covalent

between 0-2 polar covalent

greater than 2 is ionic

How many bonds does a nuetral carbon form?
4, with no lone pairs
How many bonds and lone pairs does a nuetral Nitrogen form?
3 bonds, 1 lone pair
How many bonds and lone pairs does a nuetral Oxygen form?
two bonds, 2 lone pairs
How many bonds and lone pairs does a nuetral X or halogens form?
one bond, 3 lone pairs
What are the 3 rules for resonance structures?

1. Atoms are fixed and cannot move, only electrons can move

2. Only lone-pair electrons and pi electrons – which are only found in double or triple bonds – can move

3. You can’t break the octet rule, the sum of bonds and lone pairs can’t be more than 4

What four patterns are indicative of resonance structures?

1. lone pair next to double or triple bond

2. a cation next to a double bond, triple bond, or lone-pair of electrons

3. a double or triple bond containing an electronegative atom (acetone)

4. Alternating double bonds around a ring (benzene)

How do you assign importance to resonance structures?

the more stable structures contribute more to the hybrid than unstable

 

3 factors determine stability

 

1. Fewest charges

2. Charges on the best atoms (positive charges on C(electropositive elements) and negative charges on electronegative elements (O and N))

3. Filled octets (generally, a full octet trumps charges on best atoms)

 

4. also, if the – + charges are farther apart in the compound they are less stable and higher energy, (ozone resonances are more stable than formic acids)

what are the 4 most common mistakes in drawing resonance structures?

1. forgetting charges (net charges must be equal)

2. Breaking the octet rule (never draw 5 bonds on C)

3. moving single bonds

4. not following the electron flow (always draw them flowing in a single direction)

What is an arrhenius acid?

molecules that dissociate in water to make the hydronium in H3O+

 

strong acids completely dissociate in water to form H3O+

 

acids that partially dissociate are weak

what is a arrhenius base?

molecules that dissociate in water to make hydroxide ions OH

 

strong bases completely dissociate in water to form OH

 

bases that partially dissociate are weak

Is a nucleophile an acid or base?
Lewis base
Can you be rigid in defining molecules as acids and bases?
you have to be careful because they are relative to whatever is thrown into the solution. They are relative to water. Sometimes an acid can be a base as with nitric and sulfiric acid. nitric can be a base
How do you compare acidities of molecules?

strong acids have stable conjugate bases. The conjugate base has to delocalize the – charge as it is an anion.

 

The three most important features that stabilize negative charges include electronegativity, hybridization, and size of the atom upon which the negative charge is located, the electron-withdrawing effects of neighboring electronegative atoms, and resonance effects.

What is more acidic?

 

R–OH,

R–CH3,

R–NH2

R–OH > R–NH2 > R–CH3

 

the more electronegative elements prefer to have a negative charge on them so they are more stable.

Order by acidity…

 

HF

HI

HCl

HI > HCl > HF

 

the larger the atom the more it can delocalize the negative charge. (more football stadiums to jump around to)

 

atom size trumps electronegativity

Order by acidity… assume the orbital the lone pair resides on the following hybridized orbitals

 

sp2

 

sp3

 

sp

sp > sp2 > sp3

 

lone pairs prefer more “s” like character than “p” because “s” are closer to the nucleus and they want to be closer to the nucleus

What if there are electronegative atoms on the acid, will it be more or less acidic?
More acidic because they pull they delocalize the (-) charge in the conjugate base (they act as EWG)

What do resonance structures do to stability or acidity?

 

acetic acid

 

ethanol

resonance structures are a stabilizing feature of molecules, therefore the more resonance structures the conjugate base has, the more acidic it is.

 

acetic acid has a resonance structure

how do you determine the equilibrium from the pKa?
the lower the pKa the more acidic, the equillibrium arrow goes towards the higher pKa or weaker acid
What is ethylene(ethene)?
a gaseous plant hormone that is released when the plant reaches maturity. Sometimes farmers will spray it when they want to force harvest.
what is polyethylene?
many ethylenes combined, plastic used in grocery bags, milk bottles, and other plastics
Why are alkenes very useful?
they are versatile, they can be used to synthesize many other functional groups
Name one very important alkene.

Vitamin A(retinol)

 

has 5 double bonds

 

important in vision, protects against sickness, and is used in skin care as an antioxidant

Tell me interesting things about alkynes

acetylene the most basic alkyne is a gas that is used in welding fuel because it burns cleanly and very hot 3000C

 

They are less common than alkenes in nature.

 

they just found one made from bacterium that grows in rocks that fights cancer

 

They have 180o making them linear and not stable to form rings with less than eight carbons

Where do we see aromatics in everyday life?

lots of smells(aromas)

 

Morphine

auto exhaust

soot

tabacco smoke

 

many chimney sweeps got cancer from the carcinogens in the soot chemicals, some aromatics are harmful when burned

Where do we see halides in everyday life?

they aren’t common in nature

 

they are often in compounds that are toxins

 

propellants, hairspray, spray paint, refridgerants, insecticides, teflon(contains fluorine)

 

good to synthesize

Where do we find alcohols in everyday life?

beer and wine (ethanol)

 

rubbing alcohol (isopropanol)

 

anti-freeze (ethylene glycol)

 

also sugars contain alcohol groups

where do we see thiols in everyday life?

they are stinky (R-SH)

 

in skunk spray, garlic, sewage, and rotten eggs

 

they add small amounts to methane gas commercially so you can know when the gas lines have sprung a leak

 

Cisteine, an amino acid important for protien production and keratin in hair

 

perms (you put chemicals in your hair with heat that breaks the disulfide bonds and then reforms them to stay in a different shape)

Tell me interesting things about ethers…

they are widely used as solvents in chemical reactions

 

back in the day they used diethyl ether to knock patients unconscious, it was painful to wake up though

 

ethers found in a ring are epoxides and are used in glues

where do we see carboxylic acids in everyday life?

they are abundant in nature

 

amino acids contain carboxylic acids

 

acetic acid or vinegar

tell me about esters

made from carboxylic acids

 

very sweet smelling 

 

many of the fruit smells, found in deoderants and artificial flavorings of food

 

end with the suffix -oate

where do we see amides in everyday life?

they are quite often found in nature

 

amide bonds hold all of our proteins together(amide bonds in proteins are called peptide bonds)

 

penicillin contains two amide groups

where do we see amines in everyday life?

smell of decaying animals

 

nicotine and most of the illegal drugs are amine-containing compounds

 

R-NH2 or R2NH or R3N

what are nitriles?

compounds that contain C triply bonded to N

 

suffix – nitrile

 

“cyano” groups – as a substituent

How do you draw an sp3 hybridized carbon?
two bonds in the plane of the page, one bond coming out of the page, and one bond going behind
What is a constitutional isomer?
molecules with the same molecular formula, but with atoms connected to each other in different ways
What is a stereoisomer?
same molecular forumla, same atom connectivity but with different orientations of those atoms in space
What physical properties do enantiomers share?

almost all, boiling, melting, dipole moments.

 

but they don’t rotate plane-polarized light the same way, they rotate it in opposite directions

What type of molecules rotate plane-polarized light?

only chiral molecules

 

enantiomers rotate plane-polarized light in equal and opposite directions

What is a racemic mixture?

it occurs when you mix two enantiomers in equal proportions. They do not rotate plane-polarized light because half rotates it one way and the other half rotates it the opposite way.

 

These mixtures are optically inactive the net rotation is 0

What is the relationship between chiral centers and stereoisomers?
2n where n = the number of chiral centers. If you have 5 chiral centers there are 32 possible steroismoers. You typically don’t have diastereomers unless you have more than 1 chiral centers.
What are the rules for fischer projections?

1. you can rotate it 180o and retain the stereochemical configuration, but you can’t rotate it 90o

 

2. You can rotate any three substituents on a fischer projection while holding one substituent fixed and retain the stereochemical configuration.

How do you put complex substituents into the name?
put them in parantheses 5-(1,2-dimethylpropyl)-nonane
What do ring flips do to a cyclohexane?
ring flips change all axial positions to equatorial and all equitorial positions to axial
What conformation do the large groups or substituents prefer?

they prefer equitorial because they there is less strain.  has no 1,3-diaxial strain

 

 

don’t confuse conformation with configuration.

 

you don’t change the configuration with a ring flip. They only way to change the configurations is by a chemical reaction

Draw a chair conformation

 

now a flipped one

with the normal, you start 1 up

 

with flipped start 1 down

if you have 2 substituents coming off a cyclohexane and are asked to draw the most stable chair conformation and they say it is trans, what do you do?
put the biggest group on equitorial and smallest on axial.
Draw the haworth project…
draw a squashed cyclohexane, draw lines up and down from each carbon, number 1-6, a goes down on 1 and e goes up, alternate on every carbon.
what reactions will you see from alkanes? why?

free-radical halogenation.

 

because they are essentially inert under most conditions.

What are the 3 stages of chlorination?

chlorination is a photochemical, instead of using heat to start it, it uses light.

 

1. initiation – light is shown and observed by the Cl2, it breaks the bond to form 2 Cl radicals

2. propagation – the Cl radical plucks a hydrogen atom off the CH4 this make HCl plus a methyl radical. The methyl radical attacks another molecule of chlorine to make chloromethane plus another chloride radical

3. termination – when radicals form to make stable molecules

What is the difference between bromination and chlorination?
bromine is more selevtive when deciding between the hydrogens (level of substitution). Chlorination doesn’t care as much.
how do you determine the degrees of unsaturation?

when you have fewer H than it becomes unsaturated

 

1 double bond = 1 degree of unsaturation

 

1 triple bond = 2 degrees of unsaturation

 

1 ring = 1 degree of unsaturation

 

1 degree means 2 less H’s

what is the degree of unsaturation for C3H4?
2
What if you have atoms other than H and C, how do you determine degrees of unsaturation?

Halogens(F, Cl, Br, I) – add one hydrogen to the molecular formula for each halogen present

 

Nitrogen – subtract one hydrogen for each nitrogen present

 

Oxygen and Sulfur – ignore

In which types of molecules can you have cis,trans stereochemistry?
only in rings and on double bonds. You can’t on single bonds because they can freely rotate at normal temps
What factor affect the stability of alkenes?

1. subsitution, the more non-hydrogen substituents that come off the double bond, the more stable the alkene is

 

2. Generally trans isomers of alkenes are more stable than cis (because of electron repulsion)

 

3.  

What are the 3 primary ways to form alkenes?

1. dehydrohalogenation 

2. dehydration

3. Wittig reaction

 

What is hyperconjugation?
weak overlap that occurs between the empty p orbital on the carbocation and the sigma bond of the adjacent alkyl C-H bond or C-C bond
What is the ranking of stabilization for carbocations?
primary cation ; secondary cation – allylic ; tertiary cation – benzylic cation
What is the relationship between a strong base and a nucleophile?

generally strong bases are strong nucleophiles except when the strong base is really bulky, then its hard to attach the substrate or electrophile.

 

negatively charged are stronger nucleophiles than neutral molecules

 

larger molecule are more polarizable and better nucleophiles

What does protic mean?
solvents that contain O-H or or N-H bonds. alcohols, water, and amines.
What are some good aprotic solvents for SN2 reactions?
DMSO(dimethyl sulfoxide) CH2Cl2(dichloromethane), and ethers(R-O-R)
What are good leaving groups in a SN2 reaction?

weak bases which are typically the conjugate bases of strong acids. 

 

halogens except for F

 

tosylate is the best leaving group

What are terrible leaving groups that you will never see in an SN2 reaction?

strong bases

 

(OH), (RO), and (NH2)

What are good SN1 substrates?

substrates that can make stable carbocation intermediates.

 

Things that can stabilize are resonance and alkyl groups, tertiary are the most stable 

Why do SN1 reactions prefer protic solvents?

because a protic solvent helps stabilize the cation intermediate which lowers the activation energy for the rate determining step.

 

Think about leaving a job, if the situation after you leave is more stable, you are more likely to leave.

 

For example the O on the water can help stabilize the positively charged C

What 2 reagents are widely used to reduce carbonyl compounds?

NaBH4 (sodium borohydride) – weaker reducing agent (popgun) – makes a primary alcohol from a aldehyde and a secondary alcohol from a ketone

 

LiAlH(lithium aluminum hydride – stronger reducing agent

(cannon) – makes a primary alcohol from a carboxylic acid and a primary alcohol from an ester

 

How do you make a grignard reagent?

add magnesium to an alkyl halide, it inserts itself between the C-X bond R—MgX(grignard reagent)

 

this can then be used to make alcohols

What are the reagents for making an alcohol through the markovnikov and anti-markonvnikov approaches?

1. Hg(OAc)2

2. NaBH4

 

 

1. BH3 THF

2. H2O2

What is one of the best reagents to convert alcohols to alkenes?

phosphorous oxychloride (POCl3)

 

this causes dehydration

How do you make an ether from an alcohol?
react the alcohol with Na sodium metal, this makes and alcoxide which is a strong nucleophile. This then reacts with an alkyl halide through the SN2 mechanism to form the ether
What 2 reagents can oxidize alcohols?

PCC (pyridinium chlorochromate) – weaker than jones

turns primary alcohol to aldehyde

turns secondary alcohol to ketone

 

 

Jones Reagent (Na2Cr2O7  + H2SO4 + H2O)

turns primary alcohol to carboxylic acid because it is stronger

turns secondary alcohol to ketone

 

what happens when you add hydrohalic acids to conjugated alkenes?

you have a 1,2 addition at low temps because it is the kinetic product

 

you have a 1,4 addition at high temps because it is the thermodynamic product. It takes more energy but is more stable in the end

 

draw out a conjugated diene and add a hydrogen to the 1 spot

what are good electron withdrawing groups for the dienophile in the Diels-Alder reaction?
CN (cyano groups), NO2  (Nitro groups), and all other carbonyl compounds
what are good electron donating groups for the diene in the Diels-Alder reaction?
ethers (OR), alcohols (OH), and amines (NR2)
What are MO molecular orbitals called?
psi, pronounced “sigh”

What is 

 

toluene?

aniline?

phenol?

anisole?

benzoic acid?

benzaldehyde?

styrene?

benzonitrile?

toluene? – benzene + methyl group

aniline? benzene + NH2

phenol? benzene + OH

anisole? benzene + OCH3

benzoic acid? benzene + COOH

benzaldehyde? benzene + CHO

styrene? benzene + CN

benzonitrile? benzene + CN

where do electron-withdrawing groups direct substitution?

 

where do electron-donating groups direct substitution?

1. meta

 

2. ortha and para

 

because the cations have more resonance structures

How do you know what will be a para, ortho, or meta director?
any substituent whose first atom(the one attached to the benzene) contains a lone pair of electrons will be an ortho-para director (although not necessarily a ring activator). Those substituents without a lone pair on the first atom will likely be meta directors (with the exception of alkyl groups and aromatic rings, which are ortho-para directors)
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