All MCAT Organic Chemistry Reactions Diagrams

Nucleophilic Addition

Reactions with Aldehydes and Ketones

Electrophilic Addition

Reactions with Alkenes and Alkynes

Activating or Activated

Activating a compound means making that compound reactive enough to illicit a reaction with another reagent. So when you activate a molecule you treat that molecule with another reagent to get it in the condition where it will be ready to react. The activating part is not the actual reaction we are interested in but the prelude to the reaction that preps the reagent for the reaction of interest. Like a runner jogging to warm up and get in the condition to run in the actual marathon. Activating is the reaction that usually gives reagents the charges (+) / (-) responsible for attacking other molecules or being coming attractive targets to get attacked by other molecules or making them stable enough to have leaving groups that are happy to leave - all these are ways in which the reagent is made ready to be reactive with in the main reaction.

H2 with Lindlar's catalyst

H2, Pb/CaCO3, Pb(OAc)2

Adds syn to alkyne

Alkyne to Alkene

Adds trans to alkyne (Na/NH3 )

H2 addition to an alkene (syn)

Adds H2 syn to alkene or alkyne. +/-

HBr addition to alkenes

Adds syn and anti. +/-

Markovnikov.

Rearrangements OK.

HBr addition to alkenes in H2O2

Br and H add syn. +/-

Anti-markovnikov.

HBr addition to alkenes with ROOR

Adds syn and anti. +/-

Anti-markovnikov.

ROOR are peroxides

HBr addition to alkenes with Peroxides

Adds syn and anti. +/-

Anti-markovnikov.

HBr addition to conjugated alkenes at low temperature

Get kinetic product so adds markovnikov.

Br2 addition to an alkene

Adds anti. +/-

Can add syn when tertiary carbocation.

Br2, H2O addition to an alkene

Adds anti. +/-

OH adds markovnikov.

Can add syn when tertiary carbocation.

H3O+ addition to an alkene

Adds syn and anti. +/-

OH adds markovnikov.

Same as oxymercuration.

Oxymercuration

Adds syn and anti. +/-

OH adds markovnikov.

Same as H3O+.

Conditions are:

1. Hg(OAc)2, H2O.

2. NaBH4, OH-

Hydroboration

Adds syn. +/-

OH adds anti-markovnikov.

Conditions are:

1. BH3, THF.

2. H2O2, OH-

E1 reaction

Starts with OH attacking H to form H2O which is a good LG.

Want alkene to be most substituted.

Can also form rings.

Alcohol to an Alkyl Chloride

Substitutes Cl for OH with inverted configuration. Cl is a good LG.

Anti.

Primary or secondary only.

Reagent SOCl2 (Thionyl Chloride)

Alcohol to Alkyl Bromide

Substitutes Br for OH with inverted configuration. Br is a good LG.

Anti.

Primary or secondary only.

Reagent PBr3 (Phosphorus tribromide)

Primary alcohol to aldehyde and secondary alcohol to ketone

1) PCC

Epoxide formation from alkene

Syn.

Concerted mechanism.

Uses HCO3-

Epoxide formation from alkene

Syn. +/-

Solvent often benzene.

using mCPBA a Peroxy Acid (-COOH)

Epoxide cleavage

OH and OH add anti.

Solvent is H2O.

with trace HClO4

Oxidation of alkenes

OH and OH add syn. +/-.

Solvent is NaHSO3 with OsO4, H2O

Oxidation of alkenes

OH and OH add syn. +/-.

Solvent is acetone with KMnO4, H2O, OH-

Ozonolysis with DMS - reducing

Carbonyls inserted in alkene.

1. O3, CH2Cl2, Zn

2. CH3COOH

Diels-Alder reaction with alkene

Conjugated diene reacts with alkene to form cyclohexene.

S-trans dienes must switch to s-cis dienes before reacting.

Locked s-trans dienes won't react.

Stereochemistry of alkenes and dienes maintained. +/-

Diels-Alder reaction with alkyne

Conjugated diene reacts with alkyne to form cyclohexadiene.

Stereochemistry of alkenes and dienes maintaibed. +/-

Diels-Alder reaction with cyclic diene

Can lead to bicyclic compounds.

Endo product

Alkene R is cis to outer diene R0.

Favored over exo.

Hydride reduction of an aldehyde or ketone

1. NABH4, EtOH

2. H3O+

Acetal formation from an aldehyde or ketone

Imine formation from an aldehyde or ketone

1. RNH2

2. H+

Grignard reaction

Aldol Condensation

1. NaOH

2. - H20 , Heat

Michael addition

1. Catalyst: EtO-Na+

2. Solvent: EtOH

Michael addition

1. Catalyst: EtO-Na+

2. Solvent: EtOH

Michael addition

1. Catalyst: EtO-Na+

2. Solvent: EtOH

Decarboxylation

1. - CO2

2. Heat

Decarboxylation

1. - CO2

2. Heat

Esterification

1. H+

2. MeOH

Saponification

1. NaOH

Grignard Reagent Formation

1. R-X, Mg

2. Ether (ROR)

Lithium Reagent Formation

1. Pentane

Oxidation of Alcohol (no reaction)

Oxidation of Alcohol to form an Ketone

1. PCC (oxidizing agent)

Oxidation of Alcohol to form an Aldehyde

1. KMnO4 (oxidizing agent)

or

1. NaCrO7, H2SO4

Witting Reaction

1. Ph3P-CH2 (phosphonium ylide)

DCC Coupling

1. Amine, Acid

2. DCC

Add reactions with carboxylic acids from Princeton O-chem

Peptide Bond Formation

Nucleophile: Amine

Electrophile : Carbonyl Carbon of Carboxyl