Unit 3-Organic Chemistry II

carbon in a carbonyl group is ____hybridized. this bond is____ in length and stronger, and more ____ than carbon carbon double bond in alkenes

sp2; shorter; polar

the major resonance for a carbonyl group is a ____ structure. the minor resonance has a ____ and oxygen with ____ lone pairs

ketone; carbocation; three 

the carbonyl carbon has a partial positive and will react as a ____

electrophile 

aromatic rings acts as an electron ____ group due to ____ effect making the carbonyl in the benzaldehyde less ____

donating; resonance; electrophilic 

the reactivity of an aldehyde group (or ketone) depends on strength of ____ ____ charge on carbonyl carbon (ex: benzaldehyde will ____ charge through phenol group reducing reactivity)

partial positive; stabilize

in ketone nomenclature:

• number the carbons, so the carbonyl carbon has the ____ number

• replace the alkane -e with -____

lowest; -one

for cyclic ketone nomenclature, the carbonyl carbon is assigned the number ____. when the compound has a carbonyl and a double bond, the carbonyl comes ____ 

1; first

aldehyde cannot be witin a ring because there is one ____ on one side compared to a ketone

hydrogen

in aldehyde nomenclature:

• the aldehyde carbon is labeled number ____

• the -e is replaced with -____

• if aldehyde group is attached to the ring, the suffix ____ is used

1; -al; carbaldehyde

alpha carbons are not labeled as number 1, but is the first carbon attached to the ____ carbon

carbonyl 

a grignard reagent can be used to form an ____ and that can easily be ____ to form a ____

alcohol; oxidized; ketone

Grignards are strong ____ and lewis ____

nucleophiles; bases

pyridinium chlorochromate (PCC) is selectively used to ____ primary alcohols to ____

oxidize; aldehydes 

oxidation is the loss of____ and the gain of ____. reduction is the loss of ____ and the gain of ____

hydrogen; oxygen; oxygen; hydrogen

in ozonolysis of alkenes, ____ and ____ can be isolated as products under these conditions. a double bond is oxidatively ____ by ozone followed by ____

ketones; aldehydes; cleaved; reduction

in friedel-crafts reaction, the acyl halide and aromatic ring will produce a ____

ketone 

aluminum hydrides can reduce nitriles to ____

aldehydes

diisobutylaluminum hydride (i-Bu)2AlH or DIBAL-H is commonly used for the reduction of ____

nitriles

lithium aluminum tri(t-butoxy) hydride is a mild ____agent that reacts fast with acid ____ than aldehydes 

reducing; chloride 

in nucleophilic addition mechanism, a strong nucleophile attacks the ____ carbon forming an alkoxide ion that is then ____

carbonyl; protonatd

ALDEHYDES ARE MORE REACTIVE THAN ____

KETONES

in nucleophilic addition reactions, during the ____ intermediate, STOP and look for ____ ____ attached to carbonyl carbon such as Cl and OCH3

tetrahedral; leaving group 

Witting reaction converts the carbonyl carbon into a new ____ ____ bond where no bond existed before. a ____ ____ is used as a nucleophile in this reaction

carbon-carbon double; phosphorus ylide

the carbon attached to the phosphorus in a phosphorus ylide in a ____ reaction is the new ____

wittig; nucleophile

preparation of the triphenylphosphine and unhindered alkyl halide along with butyllithium to abstract hydrogen from carbon attached to phosphorus is needed to prepare ____ ____

phosphorus ylide 

preparation of phosphorus ylides in wittig reaction: needed to become strong ____

• step 1: ____ reaction

• step 2: ____

nucleophile; sn2; deprotonation

mechanism of wittig reaction includes betaine formation and oxaphosphetane formation. this will collapse forming a ____ (ketone or aldehyde) and molecule of triphenyl phosphine oxide. the end product is an ____

carbonyl; alkene

in aqueous solution, ketone or aldehyde is in ____ with its hydrate, a ____ diol

equilibrium; geminal

in hydration of ketones and aldehydes, equilibrium constant, K is negative for ____ and hovers around 1 for ____

ketones; aldehydes

hydration of carbonyls occurs through the ____ addition mechanism where water in ____ or hydroxide in ____ serves as the nucleophile

nucleophile; acid; base

in base-catalyzed hydration of carbonyls, hydroxide ion attacks the ____ group, ____ of the intermediate gives the hydrate

carbonyl; hydration 

cyanohydrin formation mechanism is a ____ catalyzed ____ addition. attack by ____ ion on the carbonyl carbon (ketone/aldehyde) followed by ____ of the intermediate. HCN is highly toxic. the ____ on the nitrile is the nucleophile

base; nucleophilic; protonation; carboanion

the positively charged carbon atom of carbonyl group acts as a ____ and ____

electrophile; lewis acid

ammonia or primary amine reacts with ketone or aldehyde to form an ____

imine

imines are ____ analogues of ketones and aldehydes with a ____ bond inplace of the carbonyl group. the optimum ph is around ____

nitrogen; carbon-nitrogen; 4.5

imine formation includes ____-catalyzed addition of the amine to the carbonyl group with:

• step 1: ____

• step 2: ____ attacks ____

• step 3: ____

____- catalyze dehydration

• step 4: ____(OH)

• step 5: loss of ____

• step 6: ____ of H

acid

• protonation

• nuc; electrophile

• deprotonation

acid

• protonate

• water

• deprotonate

sodium borohydride, NaBH4 can reduce only ketones to ____ alcohols and aledhydes to ____ alcohols

secondary; primary

lithium aluminum hydride, LiAlH4, is a powerful ____ agent, and can reduce ____ acids and its derivatives

reducing; carboxylic

hydrogenation with catalyst can ____ carbonyl but can also with ____ and ____ bonds in molecule 

reduce; double; triple 

clemmensen reduction reduces/deoxygenates a ____ to a ____ using Zn(Hg)

carbonyl; methlyene

in catalytic hydrogenation, raney nickel (Ni-H2) attacks ____ then the ____

alkene; carbonyl

oxidation of aldehydes adds an ____ to the hydrogen attached to the ____ carbon

oxygen; carbonyl 

in formation of acetal, two molecules of ____ added to carbonyl group, and one molecule of ____ is eliminated

alcohol; water

hemiacetal formation must be ____ catalyzed, adding H+ to carbonyl makes it more ____with weak ____

acid; reactive; nucleophile

H-OTs

toslic acid (used in formation of hemiacetal)

acetal formation starts reaction with a ____ to get its final product

hemiacetal

acetals can be hydrolyzed by addition of dilute ____. excess of water drives ____ toward formation of ____ or ____

acid; equilibrium; ketone; aldehyde

in hydrolysis of acetals, redraw molecule without the two ____ single bonds

carbon-oxygen

addition of a ____ produces a cyclic acetals. the reaction is ____. this reaction is used in synthesis to ____ carbonyls from reaction

diol; reversible; protect

acetal will not react with ____, so only ketone gets reduced. hydrolysis conditions will protonate ____ and remove the ____ to restore the aldehyde

NaBH4; alcohol; acetal

acetals as protecting groups hydrolyze easily in ____ , stable in ____

acid; base 

• primary amine has ____ R group/alkyl group bonded to the nitrogen (RNH2)

• secondary amine has ____ R group/alkyl group bonded to nitrogen (R2NH)

• tertiary amine has ____ R group/alkyl group bonded to nitrogen (R3N)

• quaternary amine has ____ R group/alkyl group bonded to the nitrogen and a ____ charge (R4N+)

• one

• two

• three

• four

• positive

common names of amines are formed from the names of the ____ groups bonded to the ____, followed by the suffix -amine

alkyl; nitrogen

amine substituents are numbered as the ____ carbon number

lowest

aromatic amines are called

aniline (parent compound)

when naming a cyclic amine, the nitrogen in the amine is assigned number ____

1

nitrogen has three different groups and a lone pair, but ____ cannot be resolved due to the inversion around N except: 

• amines who chirality stems from presence of asymmetric ____ 

• ____ ____ salts with asymmetric nitrogen atoms 

• amines that cannot attain ____ hybrid or 120 degree bond angle transition state for nitrogen inversion (ex: in small ring)

enantiomers; carbon; ammonium salts; sp2

chiral amines

amines whose chirality comes from presence of chiral carbon atoms

inversion of nitrogen for chiral amines is not relevant because it will not effect chiral ____

carbon

inversion of configuration is not possible in chiral quaternary ammonium salts because there is no ____ ____ to undergo nitrogen inversion

lone pair

ammonia has a pKb of

4.74

basicity of amines:

• lone pair of electrons on nitrogen can accept proton from an ____

• alkyl amines are usually ____ than ammonia

• increasing number of alkyl groups ____ solvation of ion (2nd and 3rd amines are similar to 1st in basicity)

acid; stronger; decreases

any structural feature that stabilizes the free amine shifts the reaction to the ____making the amine a ____ base (strong bases are ____)

left; weaker; unstable

any structural feature that stabilizes the ammonium ion, shifts the reaction to the ____

right

amines are strongly ____ and can abstract a ____ from water giving an ammonium ion and hydroxide ion 

basic; proton 

the lower the pKb or pKa, the ____ the base/acid

stronger

base dissociation constant for amines symbolized as ____ and is the ____ constant for the reaction

Kb; equilibrium

in base dissociation of an amine, the ____ group stabilizes the ammonium ion making the amine a ____ base, which ____ energy of activation

alkyl; stronger; lowers

three factors that affect basicity of amines 

1. ____ group stabilization 

2. ____ effects 

3. ____ effects 

• alkyl 

• resonance 

• hybridization 

any delocalization of the electron pair ____ the base

weakens

aromatics are the ____ base, anilines are the ____

weakest; second

electrons are held more tightly by orbitals with more ____ character. the more character, the ____ the base (higher pKb). the bigger the orbital, the ____ pull and the ____ base

s; weaker; pull; stronger 

when pyrrole nitrogen is protonated, pyrrole loses its ____ stabilization. therefore, this is unfavorable and pyrrole is a very ____ base 

aromatic; weak 

aromatic amines are generally ____ basic than aliphatic (nonaromatic). this goes for nitrogen atoms as a part of the ____ ring and when the nitrogen is bonded to the ____ (ex: aniline)

less; benzene; ring

amine salt is water ____

soluble

reaction of amines with ketones/aldehydes makes an ____ or derivative when solvent is H or alkyl group 

imine

alkylation of amines by alkyl halides proceeds by the ____ reaction 

sn2

acylation of amines is a ____ ____ ____ or addition-elimination reaction

nucleophilic acyl substitution

in acyl substitution:

1. nucleophile attacks the____ carbon forming a ____ intermediate

2. expulsion of ____ ion

3. loss of ____ through the base to give rise to an ____

carbonyl; tetrahedral; chloride; proton; amide

primary and secondary amines react with acid halides to form ___. primary and secondary amines also react with sulfonyl chloride to provide an ____

amide; amide 

amides of sulfonic acid are called ____ in formation of sulfonides reaction

sulfonamides

arenediazonium salts: by forming and diazotizing an amine, position can be converted to variety of ____ groups

functional

two ways to make amines

• reductive ____

• reduction of ____

amination; nitriles

in reductive amination of primary amines, ____ can be used to reduce the oximine

LiAlH4

in reductive amination of secondary amines, the reducing agent is ____

LAH

in reductive amination, step 1 is always ____ formation and step 2 is always ____

amine; reduction

in reduction amination of teritary amines, a milder reducing agent is used ____

NaBH(OAc)3

in reduction of nitriles, nitriles (C triple bonded N) is a good sn2 ____. reduction with ____ or ____ converts nitrile to ____ amine.

nuc; H2; LiAlH4; primary