Chem 252 chapter 17

all the statements that correctly describe the mechanism for the LiAlH4 reduction of an aldehyde or ketone

The pi bond of the C=O group is cleaved in the first step of the reaction The oxygen atom of the C=O group is protonated in Step 2, after the nucleophile attacks. LiAlH4 serves as a source of hydride ions; i.e., there are no free hydride ions present.

What are the reagents that will oxidize an aldehyde to a carboxylic acid

Ag2O, NH4OH, CrO3, H2SO4, H2O

benzyl

CH2 + benzene ring

Which of the following compounds could be used to convert 1-octyne to the corresponding acetylide anion?

CH3MgBr NaH

10 carbon alkene

Dectene

Organomagnesium reagents are called __________ reagents.

Grignard

can go forward or backward with

Grignard

list the oxidizing agents:

Harsh CrO3/H2So4/H2O Na2Cr2O7/H2SO4/H2O Mild PCC,CH2Cl2

structural description of Acid Chloride

Has a chlorine atom bonded to the carbonyl group

structural description of amide

Has a nitrogen bonded to the carbonyl group

structural description of ester

Has an oygeng atom bonded to the carbonyl group

structural description of aldehyde

Has one or more hydrogens bonded to the carbonyl group

structural description of Ketone

Has two alkyl or aryl groups bonded to the carbonyl group

6 carbon alkene

Hexene

Metal Hydride Reducing Agents Milder reagents NaBH4 name the 2 aldehyde aka starting material and there products aka primary alcohol

RCHO RCH2OH R2CO R2CHOH

Metal Hydride Reducing Agents Strong reagent is LiAlH4 name the 3 aldehyde aka starting material and there product aka Primary alcohol

RCHO RCH2OH R2CO R2CHOH RCOOH RCH2OH

Ph3P

Replace the oxygen with what ever is attached to the double bond

BC

Select the reagents that will produce the desired product shown.

Why cant Aldehydes and ketones undergo sub?

They don't have a good leaving group

A C D

Which of the following structures are α,β-unsaturated carbonyl compounds?

What are the three main oxidation and reduction reactions of carbonyl starting materials?

[1] reduction of aldehydes and ketones to alcohols [2] Reduction of carboxylic acids and their derivatives [3] Oxidation of aldehydes to carboxylic acids.

A mixture of CrO3/H2SO4/H2O may be used to convert a(n) _____ into a(n) _____

aldehyde; carboxylic acid

In the carbonyl Group the carbon is _______ and the oxygen is ________. (a) electron-deficient (b) Electron Rich

carbon is electron-deficient and the oxygen is electron rich

Grignard reagents are usually prepared in ___________ _________ as solvent.

diethyl ether (CH3 CH2 OCH2 CH3)

tetra alcohols don't (do) oxidize

dont

Since both Li and Mg are very __________ metals, organolithium (RLi) and organomagnesium (RMgX) reagents contain very polar carbon-metal bonds and are therefore very reactive __________

electropositive reagents

9 carbon alkene

nonene

5 carbon alkene

pentene

Organocopper reagents (R2CuLi), also called organocuprates, have a less ________________ and are therefore less reactive.

polar carbon-metal bond

Carbonyl carbons are ____ hybridized, _____ planar, bond angle of _____

sp2, trigonal, 120

functional groups

the components of organic molecules that are most commonly involved in chemical reactions

Reduction of carboxylic acids and their derivatives: depends on the identity of ____ and ______ _______ usual gives aldehydes or 1 alcohols

z reducing agent

What is a good leaving group?

Increase in size better leaving group,

2 carbon alkene

ethene

a halogen is

fluorine (F), chlorine (Cl), bromine (Br), iodine (I), and astatine (At)

enzymes end in

-ase

Aldehyde reduce into ___ alcohol

1

During the reduction of aldehydes and ketones to alcohols, The aldehydes and ketones are reduced to ____ and _____ respectively

1 and 2 alcohols

Reaction of Grignard and organolithium reagents with α,β-unsaturated carbonyl compounds usually results in _____-addition.

1,2

What are the two broad classes of compounds containing the carbonyl Group

1. Compounds that have only carbon and hydrogen atoms bonded to the carbonyl 2. compounds that contain an electronegative atom bonded to the carbonyl (ketone)

Ketones reduce into ___ alchol

2

Reaction of a Grignard reagent with a ketone followed by hydrolysis results in the formation of a ______ alcohol.

3

Butyl

4 carbon chain as a substituent

Grignard (R-Mg-X) is

A Grignard reagent or Grignard compound is a chemical compound with the generic formula R−Mg−X, where X is a halogen and R is an organic group, normally an alkyl or aryl.

explain why ketones are less reactive than aldehydes

An aldehyde is less sterically crowded, allowing nucleophilic attack to occur more easily. The two alkyl groups of a ketone stabilize the partial charge on the carbonyl C, making it less reactive.

Select the structure of the product for the reaction shown. CH3CH2Li, THF H3o

B

An organometallic reagent cannot be used to react with a carbonyl compound that also contains an N-H or O-H group because the organometallic reagent is a strong _________ , which will deprotonate these groups instead of acting as a nucleophile. To prevent this interference, OH and NH groups must be "blocked" with a ________ group, which is removed once the synthesis is complete.

Base protecting

list of oxidizing agents for aldehydes

CrO3, Na2Cr2O7, K2Cr2O7 and KMnO4 silver oxide (Tollens's reagent)

Thus, 2-cyclohexenone, which contains both a C=C and a C=O, can be reduced into what? include the reagent used

Ketone Reagent: H2 Pd-C One equivalent of H2 reduces the C=C allylic alcohol NaBH4, CH3OH NaBH4 reduces the C=O

Wheat are the most common organometallic metals

Li, Mg, and Cu

Carboxylic acids are reduced to 1 degree alcohols with ________, LiAlH4 is too strong of a reducing agent to stop the reaction at the __________ , but milder reagents are not strong enough to initiate the reaction in the first place

LiAlH4, aldehyde

what is the synthesized from the vitamin niacin

NAD+

in cells, the reducing agent is _____

NADH

what reaction is enantioselectivity

NADH Reduction

what are the reducing agents for carbonyl ale compound

NaBH4 or LiAlH4

What are the reagents that may be used to reduce aldehydes and ketones to alcohols

NaBH4, LiAIH4

Which of the following compounds could be used to deprotonate the hydrogen from a terminal alkyne?

NaNH2 CH3Li

In the broad classes of carbonyl group what are Compounds that have only carbon and hydrogen atoms bonded to the carbonyl.

O=R-H (aldehyde) and O=R-R (ketone)

In the broad classes of carbonyl group what are Compounds that contain an electronegative atom bonded to the carbonyl.

O=R-OH (carboxylic acid) O=R-Cl (Acid Chloride) O=R-OR' (Ester) O=R-N (Amide)

8 carbon alkene

Octene

What are the general structures of common organometallic reagents

Organolithium reagents R-Li Organomagnesium reagents Grignard reagents R-Mg-X Organocopper reagents organocuprates R-R-Cu-Li

Which of the following statements are correct? Organometallic reagents will react with carbonyls before they deprotonate an O-H bond. Organometallic reagents are strong nucleophiles, but they can also be strong bases. When using organometallic reagents, N-H and O-H bonds must be protected.

Organometallic reagents are strong nucleophiles, but they can also be strong bases. When using organometallic reagents, N-H and O-H bonds must be protected.

Mechanism of NADH Reductions steps

The active site of the enzyme binds both the carbonyl substrate and NADH, keeping them in close proximity. NADH then donates H:− in much the same way as a hydride reducing agent.

Name the statements that correctly describe the mechanism of the reaction between an organometallic reagent and an aldehyde or ketone.

The intermediate of the reaction is a tetrahedral species. The final step of the reaction involves protonation of the alkoxide oxygen. The carbon group of the organometallic reagent acts as the nucleophile.

Select all statements that correctly describe the reactions of organometallic reagents. The polarity of the R-M bond determines the reactivity of the organometallic reagent. Organometallic reagents attack nucleophilic carbon atoms, especially the carbonyl group. After an organometallic reagent adds to a C=O group, the fate of the intermediate depends on the presence or absence of a leaving group.

The polarity of the R-M bond determines the reactivity of the organometallic reagent. After an organometallic reagent adds to a C=O group, the fate of the intermediate depends on the presence or absence of a leaving group.

Select all of the statements that correctly describe the structure and reactivity of α,β-unsaturated carbonyl compounds. The two π bonds in an α,β-unsaturated carbonyl compound are conjugated. An α,β-unsaturated carbonyl compound contains a double bond separated from a carbonyl group by a single bond. The α and β carbons in an α,β-unsaturated carbonyl compound are electrophilic.

The two π bonds in an α,β-unsaturated carbonyl compound are conjugated. An α,β-unsaturated carbonyl compound contains a double bond separated from a carbonyl group by a single bond.

c

What is the major product of the following reaction?

Protection groups What are the three steps of using a protection group to prevent poisonings of Grignard/alkyl lithium

[1] Convert the OH group into another functional group that does not interfere with the desired reaction. also referred to as the protecting group reaction that creates is called protection [2] Carry out the desired reaction [3] Remove the protecting group. aka deprotection

Metal Hydride Reduction of Carbonyls: The net result is

adding H:− (from NaBH4 or LiAlH4) and H+ (from H2O) is the addition of the elements of H2 to the carbonyl π bond.

LiAIH4 can reduce an aldehyde to a primary __________

alcohol

Organolithium and Grignard reagents react with aldehydes and ketones forming a new carbon-carbon bond and resulting in the formation of a(n) ______ after aqueous workup (protonation)

alcohol

The reduction reaction of aldehydes and ketones results in the formation of

alcohol

Naming al

aldehydes

what is the most useful oxidation reaction of carbonyl compounds

aldehydes to carboxylic acids

(aldehydes/ ketones) are more reactive toward nucleophilic attack Because: aldehydes are (more/Less) crowded than ketones aldehydes are (more/Less) stable than ketones aldehydes are (more/Less) reactive than ketones

aldehydes: less less more

What is a coenzyme?

an organic molecule that can function only in the presence of the enzyme.

Phenyl

benzene as a substituent

4 carbon alkene

butene

CAN/NOT do catalytic hydrogenation of carbonyls

cannot

organometallic reagents contain a _____ atom bonded to a metal

carbon

Functional Group Transformations involving organometallic compounds [1] Reaction of R-M aldehydes and ketones to afford alcohols

carbon group attack's the postive end of O= electrons go out onto the oxygen added and R group and an O- Add H2O/CH3OH (solvent) The H attaches to negative O and makes it back to neutral R group is add

NADH is what type of enzyme

coenzyme

Reduction is the _________ of C-Z bonds (usually C-O) or an_________ in the number of C-H bonds (add H sub O)

decrease, increase

what is a halogen

fluorine, chlorine, bromine, iodine, and astatine,

7 carbon alkene

heptene

oxidation is the _______ in the number of C-Z bonds (usually C-O) or a _________ in the number of C-H bonds (add O sub H)

increase, decrease

When a Grignard reagent reacts with an unsymmetrical epoxide, nucleophilic attack occurs at the _____ substituted carbon to give a(n) _____.

least alcohol

When a Grignard reagent reacts with an unsymmetrical epoxide, nucleophilic attack occurs at the _____ substituted carbon to give a(n) _____.

least, alcohol

The _____ group determines the type of reaction the carbonyl will undergo

leaving group

R2CuLi is much________reactive than either RLi or RMgX toward _______ groups.

less carbonyl

The most useful reagents for reducing aldehydes and ketones are the _____ ______ _____ : Treating an aldehyde or ketone with______ and ______, followed by ______ or _______ affords an alcohol.

metal hydride reagents, NaBH4 or LiAlH4, H2O or some other proton source

1 carbon alkene

methene

Nucleophilic Addition (1) The________ attacks the electrophilic carbonyl. The pi bond is _______, moving an electron pair out on an _______ and forming an sp3 hybridized carbon (2) ________ of the negatively charged oxygen by ____ form the addition production Net result: 2 ____ bonds broke, Two new _____ bonds, H and Nu add to π

nucleophile, broken, oxygen , Protonation, H2O, π, σ, π

General Reactions of Carbonyl Compounds Aldehydes and ketones undergo ______ _______ which means ____ and ___ and added Carbonyl compounds with a leaving group undergo__________ _______ which means _______ replaces ______

nucleophilic addition H and Nu nucleophilic sub Nu z

Nucleophilic addiction is also known as

nucleophilic attack

The mechanism for the reaction of Grignard reagents with aldehydes and ketones proceeds by ________ attack at the carbonyl carbon to form a tetrahedral alkoxide intermediate followed by __________ of the alkoxide upon addition of water or aqueous acid.

nucleophilic protonation

The reaction of lithium metal with an alkyl halide gives a(n) _______ reagent

organolithium or alkyllithium

In the carbonyl group the electronegative oxygen means the bond is ______, thus, the carbonyl carbon is electron ______

polarized, deficient

3 carbon alkene

propane

N-H, O-H, water, alcohol amides carbocyclic acids, poison's the Grignard/alkyl lithium so to prevent this aka mask it we use _______ which means we do the reaction somewhere else

protection groups

Stereochemistry of Carbonyl Reduction Butan-2-one NaBH4/CH3OH --> sp2 into sp3 makes a _____ mixture which means there is a 50% chance attacking back or front. creating two enantiomers which are: because

racemic (S)-butan-2-ol and (R)-butan-2-ol

The more polar the carbon-metal bond, the more ____ the organometallic reagent

reactive

To determine what carbonyl and Grignard components are needed to prepare a given compound, follow these two steps:

step 1: find the carbon bonded to the OH group in the product step 2: break the molecule into two components: one alkyl group bonded to the carbon with the OH group comes from the organometallic reagent, the rest of the molecule comes form the carbonyl component

Addition of Organometallics to Aldehydes and Ketones to make _____ alcohols

tetra

Why is the product racemic

the carbonyl is planar, the hydride can approach the double bond with equal probability from both sides.

NADH is the reduced form of the coenzyme

true

to remove a alkyl halides let it react with water

water

Organometallic reagents are very strong bases and readily abstract a proton from which of the following?

water, alcohols amines

A Grignard reagent has a formula RMgX where X is a halogen, and R is an alkyl or aryl (based on a benzene ring) group

where X is a halogen, and R is an alkyl or aryl (based on a benzene ring) group