organic test 4

when asked to predict the product with an organocuprate what do you see

an alkyl group with a CuLi, and either acid or an h+

does CuLi reagent (organocuprate) attack the carbonyl or the b carbon alkene (ab unsaturated compounds)

b carbon on the alkene: removes it and adds the alkyl group

if a grignard reagent is added to an ab unsaturated group, what else comes with it

acid, h+

grignard reagent reacting with an ab unsaturated carbon group, attacks carbonyl or the alkene?

it is strong, so it will attack the carbonyl and reduce to a tertiary alcohol

will an alkyl group and Li attack the carbonyl or the alkene in a ab unsaturated carbon

( alkyl group and Li along with acid (h+), will react with the carbonyl. adds the group and turns into a tertiary alcohol

which group will lose a proton easier (more acidic) based on number of carbonyl bonds

the more ketones, the more acidic

number of withdrawing groups effect on acidity of a carbonyl and chain

lowers acidity, makes resonance stable so proton will not leave

electronegativity rule and acidity of carbonyl compounds

more electronegative, more acidity

what are the two forms of a keto-enol tautomer

one has the carbonyl, and the resonance structure makes an alcohol and a double bond on the following bond

what does n-buli do

acts as a base and removes a hydrogen

1st step of crossed aldol reaction with another carbonyl group in naoh

base attacks alpha hydrogen

2nd step of crossed aldol reaction with another carbonyl group in naoh

lone electrons attack the carbonyl and kicks the oxygen electrons back; structures are combined

3rd step of crossed aldol reaction with another carbonyl group in naoh

react the oxide with oh’s proton and it is now combined

what does the aldol intermediate look like

single bond at one alpha carbon location to the “carbonyl”, add an oh at the same carbon the carbonyl used to be

how to combine completely different aldehydes and nitro carbon chains with naoet, etoh, and heat

resonate the nitro group to make a double bond, and use the double bond to attack and attach to the carbonyl, resonate the new nitrogen bond and then kick off that oxygen

how to predict the number of aldol products

if no carbonyls are present, NR. if it reacts with itself, 1 product. otherwise 4 products

how to draw aldol product (carbonyl reacted with naoet and etoh)

keep one intact and add other molecule at alpha carbon spot, single bond and add an oh a the former carbonyl carbon

how to draw the condensation product (aldol product treated with heat)

keep one product intact and add a double bond on the alpha carbon spot

how to react a single carbonyl compound (reacting w itself) with naoh and h2o

give the aldol product, not the condensation product

how to do an intra aldol reaction

count carbons and make sure to keep the ketone intact, add substituents normally and add the carbonyl adjacent to the oh single bond

any differences when reacting two carbonyls that are scary in methoxide

keep the scarier group intact, and add other carbonyl on alpha carbon

how to react two carbonyl compounds together with one in excess (methoxide and methanol)

obliterate the aldehyde, add a double bond not near the benzene or other, stick on the other group. easy.

retrosynthesis of a crossed aldol product

find either the alpha single or double bond, and slice it

if two carbonyls are in the same compound,

cyclic.

naoh, h2o and heat means

a double bond somewhere

intra aldol reactions, naoh h2o and heat

assemble the aldol by counting the main chain, and then kick off the alcohol with whatever is nearby (if heated)

what is the first step when reacting carbonyls at the alpha carbon

the alpha proton leaves

what happens in ACRxns after proton leaves

the lone pair of electrons joins the carbon it was attached to

draw three steps of alpha carbon reactions (mechanism) with a resonance form. propanal

base protonates alpha hydrogen, then the new lone pair joins to form a double bond, kicking the carbonyl off. w

what is the alpha carbon intermediate called

enolate

major factors of acidity when choosing an alpha carbon hydrogen to protonate

withdrawing groups make it worse, like ethers or amides. more carbonyls increases acidity (pick that one)

keto enol tautomerization

carbonyl to alkene back and forth

what cannot do enol reactions

alcohols and amides

what does acidic promotion do to a carbonyl (h3o+)

changes carbonyl to alcohol and adds a double bond. makes a double bond

draw the three steps of acidic promotion in cyclohexanone

protonate carbonyl, base protonates alpha hydrogen (usually water), kick c double o bond out.

what does the base pathway produce (base and an acid)

oh and an alkene next door

3 steps of base pathway (cyclohexanone)

same as acidic promotion but the carbonyl forms an oxide first, (resonance) then base deprotonates alpha hydrogen and adds an alkene, oxide deprotonates a base, and forms an alcohol

what are the 4 steps to the general alpha carbon reactants and products

acetone, methoxide////////lone pair acetone and ethanol. favors left side

what does reacting acetone with an h product give

h2 gas and lone pair acetone

secondary amine group (complicated) reacted with Li something

deprotonates the amine base and ads a negative charge (this forms LDA) which is useful

amine plus nbutyl amine

LDA

draw LDA formation mechanism

diisopropyl amine deprotonated by Lich3ch2ch2ch3 lone pair

which base to pick lda or methoxide

methoxide because it is safer to use, less reactive

how to pick which alpha carbon hydrogen to protonate

which hydrogen is “busier” or in between carbonyls? deprotonate that one and make the lone pair there

what does alpha halogenation do

keeps carbonyl and adds a halogen; adjacent carbon

reagents for alpha halogenation

br 2 and acid

practice drawing mechanism for alpha halogenation

cyclohexanone(adjacent methyl)

full mechanism for alpha halogenation

protonate carbonyl with acid, bring electrons back down and alkene attacks one br and curved arrow the other br, —→final product

basic halogen promotion (look up methyl cyclohexanone)

add a br next to the carbonyl

carbonyl reacting with oh, and double bond

a base forms the enolate with oxide and an alkene

what is a good processing step for adding a carbon group

h+ br2 to make a good leaving group next door

why use hplus and a base???

ask them

aldehyde reacted with h+ and base, alkyl sufide

add to the carbon chain side

what is a second step to add an alkene

h+ and i2 to add I leaving group, and then use pyridine to make an e2 reaction

when do you do the special knock of the alkene

e2 reaction toward carbonyl first

what does 2 equivalents of LDA do

deprotonates an oxygen(alcohol) and gets rid of an alpha carbon proton

mechanism drawn for alpha halogenation of carboxylic acid

deprotonate, lone pair joins, knocks off carbonyl, new double bond attacks br-br, then reacted with acid

what is the purpose of the hell-vollard zelinsky

to add a bromine on the other side (not normal leaving group) but halogenate alpha carbon

what are the reagents for hell-volhard zelinsky

pbr3, br2//h20

draw the mechanism for hell volhard zelinsky

add pbr3 on normal side, resonate the carbonyl one bond over, attack br-br with the new alkene. 2 bromines result on the chain, react with h2o and remove normally placed br

N-halosuccinimide

n-x to carbonyl (2) both sides of a six membered ring

what does n halo succinimide do

add halogen to alpha carbon (like hell volhard zelinsky)

reagents to use with n halo succinimide

socl2 (leaving group) with N halo succinimide, water (oh group), nh3 to replace added leaving group

what is another word for alpha alkylation

tautomerization

two steps to alpha alkylation

deprotonate carbonyl with LDA, react via sn2 alkylation

what does alpha alkylation accomplish

adds an alkyl group

reagents for alpha alkylation

thf with LDA, alkyl halide group

which side does LDA go?

cold LDA adds carbons at the less substituted side

draw two resonance structures for each pathway of methyl cyclohexanone reacted with LDA and THF.

same structure with a lone pair on either side and then forming a double bond enolate

which product takes less activation energy, thermodynamic or kinetic

kinetic takes less energy, the less substituted side in that case

when to use lda and thf/ with an alkyl halide

reacting with carbonyls and making a double bond; esters and nitriles

why does the thermodynamic product for alpha alkylation happen on the more substituted side

steric strain requires more energy

a cyclic ester reacted with LDA, THF and ch3ch2I gives what

an alkyl group attached to the alpha carbon

what does a nitrile reacted with LDA, THF and EtI give

isopropyl nitrile; the ethanol adds as an isopropyl

react 3 carbon nitrile with LDA, THF and EtI

isopropyl 4 carbon nitrile

what two types of compounds react in an aldol reaction

aldehyde and alcohol

what two types of compounds are reacted in an aldol (not the name)

enolate, and carbonyl

what does propanal reacted with oh and h2o give

“aldol product” reacted with itself, but not condensed yet::::: 5 carbon chain aldehyde with a methyl and oh

how to name aldol products

alpha carbon hydroxide: alpha hydroxyaldehyde….if on the beta carbon: beta hydroxyaldehyde

if an aldol product is heated what happens

ab unsaturated aldehyde forms. double bond at the alpha carbon

what is the mechanism for making an ab unsaturated carbon called (with heat)

e1cb

draw the first part of the e1cb mechanism on propanal

the oh (oh h2o reactants) depronates an alpha hydrogen and the lone pair kicks electrons off the oxygen and then the new double bond reacts with another molecule and makes the aldol product (methoxide instead)

what is the second part of the e1cb mechanism after the two molecules join and an oxide is formed (propanal)

it protonates a water molecule, then oh deprotonates the alpha carbon hydrogen….that last step creates a lone pair that knocks off the carbonyl…it swings back and goes to the other side getting rid of the new alcohol

what does the stork reaction accomplish

turns a carbonyl into an e2 enamine group

why would the stork reaction be used

not as harsh

what is the second “part” of the stork reaction

hydrolysis of enamines, or the backwards variant

example of starting and ending products for the stork reaction

carbonyl cyclohexanone turned into double bond on less substituted with amine group attached

overall transformation of stork reaction

carbonyl to a double bond with an amine group

when an amine is formed with a double bond (stork reaction), what happens when it reacts with an R-X halogen

the kinetic product adds the alkyl group to the nitrogen on the amine::: the thermodynamic product forms an imine and attaches the r group on the alpha carbon (no more double bond)

which product is wanted from the stork reaction

the thermodynamic heated imine

stork reaction: when treated with acid what happens to the imine

carbonyl group replaces it for some reason

what three steps would take place in stork reaction acylation

amine base and acid, 2. acyl chloride, 3. acid… this keeps the carbonyl and adds the acyl group keeping only its carbon chain

run through the whole stork reaction mechanism for cyclohexanone

first carbonyl adds the whole amine group and replaces double for the single bond (acid to add carbonyl). reacts with an alkyl halide to add the R group (thermodynamic), then reacts with acid to restore carbonyl

what do the three steps of acyl stork reaction start/produce

cyclohexanone to cyclohexanone with a carbonyl chain group adjacent to it

michael addition summary words

conjugate addition via 1,4 carbon

what is the point of a michael addition

add a molecule to the middle of two ketones

basic mechanism of a 1,2 michael addition in acetone

nucleophile attacks carbonyl and adds itself

what does a beta addition of a nucleophile look like (unsaturated ab carbonyl)

an ab unsaturated carbonyl just has a double bond one carbon away, a nucleophile either adds to the chain, or the oxygen kicks it off (not helpful)

what is the intermediate of a michael addition called

an enolate

1,2 addition vs 1,4 addition

1,2 addition adds to the carbonyl, and the 1,4 addition adds to the beta carbon hydrogen