Organic Chemistry Solvents

Characteristics of polar protic solvent?

• hydrogen bonding with N or O

• stabilize carbocation

• favor SN1

Example of polar protic solvents?

water, MeOH, EtOH, NH3

Characteristics of aprotic solvent?

• no hydrogen bonding

• does not hinder nucleophiles

• favor SN2

Example of aprotic solvent?

DMSO, DMF, acetone, THF

Where do SN2 reactions attack and do they result in inversion of stereochemistry?

alpha position; yes

Where do SN1 reactions attack and what does it produce?

attack the carbocation; attack from either face and will produce racemic mixture if it is chiral

When is the Zaitsev product formed?

during elimination reactions when base is UNHINDERED; on the more substituted alkene

When is the Hofmann product formed?

during elimination reactions when base is HINDERED; on the less substituted alkene

What is the stereochemistry of E1?

Zaitsec, E alkene is favored over Z

What occurs when reacted with Hg(OAc)2?

oxymercuration- demercuration

anti-addition across alkene bond with Markovnikov specificity

• adds OH and H

What occurs when reacted with:

1. BH3, THF?

2. H202, OH-, H20

syn-addition with ANTI-markovnikov across alkene

• add OH and H

What occurs when reacted with:

cold, dilute KmnO4

OR

1. OsO4

2. NaHSO3/H2O

syn-addition (meso compound)

• add OH on both sides of alkene

What occurs when reacted with:

Br2, CCl4

anti-addition of Br across alkene

What occurs when reacted with:

1. O3

2. (CH3)2S (reducing) OR Zn, H2O

ozonolysis; ketone and aldehyde

What occurs when reacted with:

1. O3

2. H202 (oxidizing)

ozonolysis; ketone and carboxylic acid

What occurs when reacted with:

1. KMnO4/heat

2. H3O+

oxidative cleavage; ketone and carboxylic acid

1. H2

2. Pd/C

STRONG; reduce alkyne to alkane

1. H2

2. Lindlar’s catalyst

PARTIAL: alkyne to CIS-alkene

1. Na/Li

2. NH3 (l)

PARTIAL: alkyne to TRANS-alkene

1. HgSO4

2. H2SO4, H20

HYDRATION of terminal alkynes (markovnikov)

• ketone

1. Sia2BH-THF

2. H202, OH-, H20

HYDRATION of terminal alkynes (anti-markovnikov)

• aldehyde

For terminal alkyne:

1. O3

2. H2O

yields carboxylic acid and CO2

For internal alkyne:

1. O3

2. H2O

two carboxylic acids

1. Br2

2. FeBr3

bromination

1. CO, HCl

2. AlCl3

formylation

• aldehyde

1. H2NNH2/ N2H4

2. OH-, heat

wolff-kishner reduction

• reduce ketone, aldehyde to alkane under BASIC conditions

1. Zn (Hg)/ HCl

2. heat

reduce ketone/aldehyde under ACIDIC conditions to alkane

What is a hemiketal?

A hemiketal is a compound formed from the reaction of an aldehyde or ketone with an alcohol, containing both OR and OH attached to the same carbon atom.

What is a ketal?

A ketal is a compound formed from the reaction of a ketone with an alcohol, resulting in a carbon atom bonded to two OR groups.

What is a hemiacetal?

A hemiacetal is a compound formed from the reaction of an aldehyde with an alcohol, featuring one OR group and one OH group attached to the same carbon atom.

What is an acetal?

An acetal is a compound formed from the reaction of an aldehyde or a ketone with an alcohol, resulting in a carbon atom bonded to two OR groups.

Reaction with (C6H5)3P (Pph3) is named what?

Wittig reaction, treatment of aldehyde or ketone with phosphorus ylide forms alkenewith the formation of a carbon-carbon double bond.

What occurs after reacting with:

1. LiAlH4

2. H30+

VERY STRONG; Reduce aldehyde, ketone, esters, acids and amides to alcohol

Reaction with ___ results in:

1. NaBH4

MILD; reduce aldehyde and ketones only to alcohol

Reaction with LTBA results in:

MILD; reduce acyl chloride to aldehyde

Reaction with:

1. LiAlH4

2. H2O

amide to amine, reduce C=O

Primary alcohol reacted with PCC results in?

OXIDATION, aldehyde

Primary alcohol reacted with KMnO4 or CrO3/H2SO4 results in?

carboxylic acid

Reaction wit K2Cr207 from primary alcohol results in?

OXIDIZING; carboxylic acid

Reaction with PBr3/pyridine from primary and secondary alcohol results in?

• alkyl bromide

• alkyl bromide (inversion of stereochemistry) from secondary

Oxidative cleavage of 1,2 diol with HIO4 results in?

ketone and aldehyde

What is the swern oxidation?

primary alcohol reacted DMSO, (COCl)2 [oxalyl chloride] and Et3N resulting in aldehyde

OR secondary alcohol converted to ketone

What is the self-aldol condensation?

two molecules of an aldehyde or ketone react in the presence of a base (NaOH, H2O) to form aldol (aldehyde and alcohol) which can further dehydrate to yield an α,β-unsaturated carbonyl compound.

What is the crossed aldol condensation?

two different aldehydes or ketones react in the presence of a base to form a mixture of aldol products, which can dehydrate to yield α,β-unsaturated carbonyl compounds.

What is the intramolecular aldol condensation?

A reaction where two functional groups within the same molecule react to form a cyclic compound, typically yielding a product that features a carbonyl group and an alkene.

What is the self-claisen condensation?

A reaction where two esters react in the presence of a base (CH30-, H3O+) to form a β-keto ester or β-dicarbonyl compound.

What is the crossed claisen condensation?

A reaction involving two different esters or an ester and a carbonyl compound, catalyzed by a base, leading to the formation of β-keto esters or β-dicarbonyl compounds.

What is the dieckmann condensation?

A reaction where two ester functional groups in the same molecule react in the presence of a base to form a cyclic β-keto ester.

What is interchangeable with grignard reagents (R-MgBr)?

R-Li

When reacting a Grignard reagent to epoxide, where will it attack?

The less sterically hindered carbon atom of the epoxide.