Organic Chemistry Test Answers – Flashcards

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

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

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)

stereoisomers that are non-superimposable mirror images

greek for "opposite"

[alpha]=alpha/c*l

[alpha]=specific rotation

alpha=observed rotation

c=concentration (g/mL)

l=path length/length of tube (dm)

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

alpha = optical activity?

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

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

nucleus lover

-region of high electron density

-attracted to nuclei

electron lover

-region of low electron density

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

methyl;1^o;2^o;3^o

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

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

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

methyl;1^o;2^o;3^o

there is more steric hinderance with 3^o

trans - latin

entgegen (E) - German "across"

cis - latin "together"

(z) Zusamen - german for "together"
 

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

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

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

The result is NR no reaction

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

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

benzaldehyde - (rosy smell)

cinnimaldehyde - (cinnamon smell)

acetaldehyde - (

acetone (german for ketone)

write ketone at the end

or add "one" after the alkane

add "oic acid" to the end of the alkane ex: butanoic acid

this will be at the beginning or end of the chain

add amine to the end "cyclohexanamine"

if it's not highest priority, use "amino"

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

meta is not favored(1,3)

a benzene ring with a methyl group attached

a benzene ring with an aldehyde group

it has the smell of almonds

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

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

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

0 = purely covalent

between 0-2 polar covalent

greater than 2 is ionic

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

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)

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)

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)

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

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

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.

R--OH > R--NH₂ > R--CH₃

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

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

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

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

Vitamin A(retinol)

has 5 double bonds

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

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

They are less common than alkenes in nature.

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

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

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

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

beer and wine (ethanol)

rubbing alcohol (isopropanol)

anti-freeze (ethylene glycol)

also sugars contain alcohol groups

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)

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

they are abundant in nature

amino acids contain carboxylic acids

acetic acid or vinegar

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

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

smell of decaying animals

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

R-NH₂ or R₂NH or R₃N

compounds that contain C triply bonded to N

suffix - nitrile

"cyano" groups - as a substituent

almost all, boiling, melting, dipole moments.

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

only chiral molecules

enantiomers rotate plane-polarized light in equal and opposite directions

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

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

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

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

with the normal, you start 1 up

with flipped start 1 down

free-radical halogenation.

because they are essentially inert under most conditions.

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

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

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

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.  

1. dehydrohalogenation 

2. dehydration

3. Wittig reaction

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

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

halogens except for F

tosylate is the best leaving group

strong bases

(OH^-), (RO^-), and (NH₂^-)

substrates that can make stable carbocation intermediates.

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

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

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

LiAlH₄ (lithium aluminum hydride - stronger reducing agent

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

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

1. Hg(OAc)₂

2. NaBH₄

1. BH₃ THF

2. H₂O₂

phosphorous oxychloride (POCl₃)

this causes dehydration

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

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

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

1. meta

2. ortha and para

because the cations have more resonance structures