ochem reactants

Acid-Catalyzed Hydration

H3O+

Oxymercration

1. Hg(OAc)2

2. H2O

3. NaBH4

Dihydroxylation

1. KMnO4

2. H2O2, NaOH

Hydroboration-Oxidation

1. BH3, THF

2. H2O2, NaOH, H2O

Anti-Dihydroxylation

1. MCPBA

2. H3O+

Oxidative Cleavage (Alkene)

1. O3

2. DMS

Halogen Addition

Br2

Halohydrin Formation

1. Br2

2. H2O

Hydrohalogenation

H-X

Anti-Hydrohalogenation

1. H-X

2. H2O2

Catalytic Hydrogenation

1. H2

2. Pt

Deprotonation

NaNH2

Preperation of Alkyne

1. HX

2. NaNH2, NH3

3. H2O

Reduction to Alkane

1. (xs) H2

2. Pt

Reduction to Cis Alkene

1. H2

2. Lindlar's Catalyst

Reduction to Trans Alkene

1. Na

2. NH3

Addition of Halogen

HX

Anti-Addition of Halogen

1. HBr

2. H2O2

Halogenation

1. X2

2. CCl4

Hydration

1. H2O, H2SO4

2. HgSO4

Hydroboration

1. BH3, THF

2. H202, NaOH

Oxidative Cleavage (Alkyne)

1. O3

2. H2O

Alkynation

1. NaNH2

2. Me/Et-LG

What yields anti-Markovnikov's products for Alkynes?

Radical Addition of HBr and Hydroboration

What yields trans major products for Alkynes?

Reduction using 1. Na and 2. NH3 and Halogenation

What causes Keto-Enol Tautomerization?

Hydration of Alkynes

What yields anti-Markovniko products for Alkenes?

Hydroboration-Oxidation and Anti-Hydrohalogenation

What has syn stereospecificty for Alkenes?

Hydroboration-Oxidation, Dihydroxylation, and Catalytic Hydrogenation

What has anti stereospecificty for Alkenes?

Anti-Dihydroxylation and Br2 Addition

Acid-Catalyzed Hydration

Markovnikov

Racemic R/S

Oxymercuration

Hydroboration-Oxidation

Dihydroxylation

Anti-Dihydroxylation

Oxidative Cleavage

Radical Bromination

Halohydrin Formation

Hydrohalogenation

Hydrohalogenation

Catalytic Hydrogenation

Deprotonation

Preparation of Alkyne

Reduction to Alkane

Reduction to Cis Alkene

Reduction to Trans Alkene

Addition of HX

Radical Addition of HBr

Halogenation

Hydration

Hydroboration

Oxidative Cleavage (Alkyne)

Alkylation

TERM

Reagent 6

DEFINITION

1. Br2

TERM

Reagent 7

DEFINITION

1. Br2, H2O

TERM

Reagent 8

DEFINITION

1. RCO3H 2. H3O+

TERM

Reagent 9

DEFINITION

KMnO4, NaOH (Cold)

TERM

Reagent 9

DEFINITION

1. OsO4 2. NaHSO3, H2O

TERM

Reagent 10

DEFINITION

1. O3 2. DMS

TERM

Reagent 1

DEFINITION

HX

TERM

Reagent 2

DEFINITION

1. HBr 2. H2O2

Electrophilic Addition

CH3CH=CHCH3 + HBr

Follows Markovnikov's rule

Acid-Catalyzed Hydration Reaction

CH3CH=CH2 + H2O

Follows Markovnikov's rule

1,2 Shift

3-Dimethylbut-1-ene + HCl

Occurs to produce a more stable carbocation

Can occur in any reaction (electrophilic addition, hydration, etc)

Generation of a Halohydrin

1-methylcyclopentene + H2O + Br2

Both regioselective and antistereoselective (i.e., the two groups have to be trans of each other)

Halogen binds to the less substituted carbon

Oxymercuration reduction of an alkene

1-methylcyclopentene + (1) HgOAc (2) NaBH4

Essentially the same as the Markovnikov addition of H2O to an alkene

OH bonds to the more substituted carbon and HgOAc to the less substituted carbon; reduction by NaBH4 replaces the HgOAc with an H

Occurs without rearrangement, indicating that a carbocation isn't formed

Hydroboration-oxidation reaction of an alkene

1-methylcyclohexene + (1) BH3 (2) H2O2, NaOH

Non-Markovnikov hydration of an alkene; i.e., the OH group is added to the less substituted carbon

Occurs without rearrangement

Involves the cis-addition of H-OH

Oxidation of an alkene with OsO4 or MnO4

Cyclopentene + OsO4

Converts an alkene to a 1,2 diol

Involves the cis-addition of an OH group to each carbon of a double bond

Ozonolysis of an alkene

2-methyl-2-pentene + O3

Cleaves the carbon-carbon double bond and leaves two C=O groups in its place

Forms a ketone and an aldehyde (the aldehyde is only stable if there are no oxidizing agents present)

Halogenation of Alkanes

CH3CH2CH3 + Cl2

is a radical substitution reaction; regioselective for the more substituted carbon

Radical chain reaction

Products are a racemic mixture

NBS Reaction

Cyclohexene + NBS

Useful method for carrying out allylic bromination (the allylic carbon is the carbon next to the double bond)

Radical chain reaction initiated by light

Reaction of alcohols with reactive metals

CH3OH + Na

Gives metal alkoxide ions and hydrogen gas

alkoxide ions are very basic

Reaction of alcohols with hydrogen halides

2-Methyl-2-Propanol + HCl

2,2-Dimethyl-1-propanol + HBr

1-Butanol + HBr

forms haloalkanes

2º and 3º occurs through SN1 mechanism

branched 1º occur with rearrangements via SN2

unbranched 1º occur through SN2 mechanism

Reaction of alcohols with PBr3

CH3CH2OH + PBr3

Forms bromoalkanes

only works with primary and secondary alcohols

occurs via SN2 mechanism, so no rearrangements

Reaction of alcohols with SOCl2

1-Heptanol + SOCl2

Forms chloroalkanes

only works with primary and secondary alcohols

occurs via SN2 mechanism, so no rearrangements

Reaction of alcohols with MsCl or TsCl

Cyclohexanol + TsCl

Forms haloalkanes

only works with primary and secondary alcohols

occurs via SN2 mechanism, so no rearrangements

Acid-Catalyzed Dehydration of an Alcohol

tert-Butyl alcohol + H2SO4

2-Butanol + H2SO4

1-Butanol + H2SO4

Forms alkenes

the more substituted the alchol, the easier it is to dehydrate

dehydration of 1º and 2º alcohols is often accompanied by rearrangement

occurs via an E1 mechanism (i.e., carbocations are formed)

the most stable product predominates

Pinacol rearrangement of diols

2-Methyl-1,2-Propanediol + H2SO4

the more substituted OH group is the one that leaves first

results in a ketone/aldehyde

Oxidation of alcohols with Jones Reagent

1-Hexanol + H2CrO4

Cyclohexanol + H2CrO4

1º are oxidized to aldehydes/carboxylic acids

2º are oxidized to ketones

3º are not oxidized

Oxidation of alcohols with PCC

1-Butanol + H2CrO4

1º are oxidized to aldehydes

2º are oxidized to ketones

3º are not oxidized

Reaction of alcohols with POCl3

1-Butanol + POCl3

forms an alkene via a E2 mechanism

Williamson Ether Synthesis

CH3CH2CH2ONa + CH3CH2Br

Involves the nucleophilic displacement of a halide by an alkoxide ion via an SN2 mechanism

works best on 1º halides, less well on 2º halides, and fails completely on 3º halides due to competition with E2 mechanism

Ether Formation by Acid-Catalyzed Dehydration of Primary Alcohols

CH3CH2OH + H2SO4

Works best with 1º alcohols, less well with 2º alcohols, and fails completely with 3º alcohols due to competition with dehydration to an alkene

Occurs via an SN2 mechanism

Cleavage of Ethers by HX

CH3OCH3 + HBr

Produces an alcohol and an alkyl halide

1º reacts via SN2 mechanism

2º and 3º react via SN2 mechanisms

the alcohol reacts further with the HX to form another molecule of alkyl halide

Synthesis of an Ether from an Alkene

2-methylpropene + methanol

can only be done with alkenes that form stable carbocations and primary alcohols

alcohol acts as a weak nucleophile to attack the carbonation formed by the alkene via an SN1 mechanism

requires an acid catalyst

Synthesis of Epoxides from Halohydrins

cyclohexene + (1) Cl2 (2) NaOH

occurs via an internal SN2 mechanism

configuration is conserved

can only occur in basic conditions

Oxidation of alkenes with peroxyacids (MCPBA)

cyclohexene + RCOOOH

forms epoxides

configuration is conserved

the steps of this reaction are concerted

Acid Catalyzed Ring Opening of Epoxides

Ethylene Oxide + H2O

produces trans glycols

nucleophile attacks more substituted carbon

Nucleophilic Ring Opening of Epoxides

Propylene Oxide + CH3ONa

nucleophile attacks less substituted carbon

occurs via an SN2 mechanism

attack of the nucleophile is anti to the leaving group, resulting in an inverse in configuration

Reaction of Alkynes with NaNH2

CH3CCH + NaNH2

forms an alkyne; if terminal, it forms an alkyne carbocation

the carbocation can then act as a strong nucleophile and react with other molecules (e.g., alkyl halides, acids, etc)

Electrophilic addition of alkynes

CH3CCCH3 + Br2

CH3CCH + HBr

addition of a halogen gives a dihaloalkene; the halogen atoms are added anti to one another

same mechanism as addition to alkenes

follows Markovnikov's rule

Hydroboration-Oxidation of an Alkyne

follows anti-Markovnikov addition; the OH group adds to the less substituted carbon

forms an enol, which immediately rearranges to form a more stable ketone/aldehyde

Acid-Catalyzed Hydration of an Alkyne

CH3CCH + H2O

Follows Markovnikov's rule; the OH group adds to the more substituted carbon

forms an enol, which immediately rearranges to form a more stable ketone/aldehyde

Catalytic Reduction of Alkynes

CH3CCCH3 + H2 (Lindlar)

CH3CCCH3 + 2H2 (Ni)

Forms cis alkene with Lindlar catalyst

Forms alkane with other transition metal catalyst

Dissolving Metal Reduction of Alkynes

CH3CCCH3 + 2Na (NH3)

forms trans alkenes

involves the anti addition of two hydrogen atoms to the triple bond