Organic 1 + 2 Mechanisms for ACS final

ACS final stuff you need to know :) NOTE WHEN I SAY FORMS ENANTIOMERS, THIS IS ONLY THE CASE IF PRODUCT ISN'T ACHIRAL. If it had a chiral center before, it forms diastereomers. Also ensure it's not meso!

Radical halogenation

Hydration of alkenes

H3O+ or H2O/H2SO4… CH3OH also works, but results in OCH3 being added instead of OH
- results in OH on most sub. carbon
- Markovnikov
- not stereoselective
- 1,2 hydride shifts and carbocation rearrangements can occur
- produces enantiomer (carbocation formation)

Halogenation of alkenes

Br2 or Cl2 (not I2)
- results in 2 halogens being added anti.
- no regiochem
- Anti addition
- produces enantiomers

Hydrohalogenation

HBr or HCl
- results in halogen being added on most sub. carbon
- Markovnikov
- not stereoselective
- 1,2 hydride shifts and carbocation rearrangements can occur
- produces enantiomers

Halohydrin

Br2 or Cl2 and H2O or CH3OH as solvent
- results in halogen being added anti to OH or OCH3, OH or OCH3 being added to most sub carbon.
- markovnikov
- anti addition
- produces enantiomers

Oxymercuration demercuration

1) Hg(OAc)2, H2O 2) NaBH4
- results in an OH on most sub carbon and H on other.
- Markovnikov
- anti additon ONLY FOR OXYMERCURATION PART, which results in anti OH and HgOAc. Demurcuration is NOT stereospecific, so you can have syn or anti.
- results in enantiomers

Hydroboration Oxidation

1) BH3 THF 2) H2O2, NaOH
- results in OH on least sub carbon, H on most, OH and H on same side
- anti-markovnikov
- syn addition
- results in enantiomers

Catalytic hydrogenation

H2/Pt or H2/Ni or H2/PdC
- results in alkane with 2 H added to same side
- no regiochem
- syn addition
- results in enantiomers

Peroxy acid expoxidation

m-CPBA
- results in epoxide that is trans or cis
- No regiochem
- Keeps trans/cis shape. Aka a trans alkene will produce a trans epoxide, and vice versa
- Syn addition
- trans alkenes and unsymmetrical cis alkenes will produce enantiomers, but symmetrical cis alkenes will produce meso compounds

Epoxide formation from halohydrins

Base (NaOH, NaH, etc.)
- results in epoxide that lacks halogen
- occurs via SN2 rxn!

Epoxide opening under acidic conditions

Epoxide opening under basic conditions

Osmium tetraoxide

1) OsO4
- results in 2 OHs being added to the same side
- no regioselectivity
- syn addition
- produces enantiomers

Oxidative cleavage

Carbene formation

Hydrohalogenation of an Alkyne

HCl or HBr
First addition results in vinyl halide, second addition results in geminal halide
- first addition is anti addition and maokovnikov

Halogenation of an Alkyne

Cl2 or Br2
1st addition results in trans alkene (anti addition), second addition results in a product with 4 halogens

Acid catalyzation of an Alkyne?

Hydroboration of an Alkyne

1) BH3/THF 2) H2O2, NaOH
forms enol (OH bound to an alkene) → tautomerizes to aldehyde (terminal alkyne)
- anti-markovnikov

Catalytic hydrogenation of an Alkyne

2 H2/Pt or Pd/C
- full reduction to alkane
- syn addition

Lindlars Cat.

H2/Lindlars catalyst
- partial reduction aka reduces to cis-alkene
- syn addition

Dissolving metal reduction

Na/NH3
- partial reduction aka reduces alkyne to trans-alkene
- anti addition

Allylic bromination

NBS/Peroxide
- bromine adds to allylic position carbon (next to double bond)
- radical mechanism

Tosylate formation

TsCl, pyridine
- converts OH to OTs (good leaving group)
- retains stereochemistry

Grignard reagents as bases

SN2 rxns

- backside attack
- 1° or 2° alkyl halides best
- inversion of stereochem
- no carbocation rearrangement
- polar aprotic solvent

SN1 rxns

- carbocation intermediate
- 3° or 2° alkyl halides
- racemic mixture (if chiral)
- rearrangements possible
- polar protic solvent

E2 rxns

- strong base
- no rearrangement
- Zaitsev product (more substituted alkene favored)

E1 rxns

- weak base, heat
- carbocation intermediate
- Zaitsev product
- rearrangements possible

Diels Alder

- diene + dienophile
- concerted [4+2] cycloaddition
- dashed =
- wedge =
- syn addition (endo preference)
- diene must be in

EAS Fluorine

F-TEDA
- Fluorine added to ring.
- ortho/para-directing, deactivating

EAS Chlorine

Cl2/FeCl3
- Adds Cl to ring.
- ortho/para-directing, deactivating

EAS Bromine

Br2/FeBr3
- Adds Br to ring
- ortho/para-directing, deactivating

EAS Iodine

Aromatic Nitration

HNO3 + H2SO4
- adds NO2
- meta-directing, deactivating

Aromatic Sulfonation

SO3 + H2SO4
- Adds adds SO3H
- meta-directing, deactivating

Friedel Crafts Alkylation

R–X + AlCl3
- adds R group
- carbocation rearrangement possible
- ortho/para-directing

Friedel Crafts Acylation

RCOCl + AlCl3
- adds RCO group
- no rearrangement
- ortho/para-directing

Benzylic oxidation

Benzylic Bromination

Substitutes benzylic hydrogens only.

reduction???

Wolff-Kishner

Basic conditions.

Clemmsen reduction

Works on aldehyde and ketones (same result for both)

Acidic conditions.

Nucleophilic Aromatic Substitution
Addition—Elimination
Meisenheimer complex

Nucleophilic Aromatic Substitution
Elimination—Addition
Benzyne

Reduction via NaBH4

Reduction via LiAlH4

Reduction via Grignard

Works with both aldehydes and ketones.

Ketones turn into a tertiary alcohol

Aldehyde turns into a secondary alcohol.

TMS protection

Hydride additon

Hydration of aldehyde

Hydration of ketone

Acetal formation

Base nucleophilic addition rxn

Acid catalyzed nucleophilic addition rxn

Cyanohydrin

DB O becomes OH and a CN is added

Cyclic acetals as protecting groups

Thiol formation

Thiolacetals

Imines

Requires a 1* amine

Enamines

Works for both aldehydes and ketones

Requires a 2* amine.

Witting rxn

Cyanide addition

Additions to alpha and beta unsaturated ketones/aldehydes

Nitrile formation SOCl2 and 1 amine

Nitrile formation SN2

Nitrile reduction w/ LiAlH4

Nitrile with Grignard

Nitrile hydrolysis acidic conditions

Nitrile hydrolysis basic conditions

Carboxylic acid formation w/ CO2 + Grignard

Carboxylic acid to acid chloride w/ SOCl2

Carboxylic acid to anhydride w// heat

Carboxylic acid to ester via SN2

Carboxylic acid to ester Fischer esterification

Fancy name for “Add ester with acid”.

Must have an excess of alcohol.

Carboxylic acid to amide via heat

Carboxylic acid to amide peptide synthesis
DCC activation

Carboxylic acid to amide peptide synthesis
Coupling

Carboxylic acid to amide peptide synthesis
Boc protection

Carboxylic acid to amide peptide synthesis
Boc deprotection

Acid halide to anhydride w/ carboxylate

Cl is ejected and CO2- takes over.

Acid halide to ester w/ alcohol and base

Acid halide to ester w/ alkoxide

Acid halide to amide

+ Ammonia —> 1 amide

+ RNH2 —> 2 amide

+ R2NH —> 3 amide

Acid halide reduction w/ LiAlH4

Acid halide reaction w/ excess grignard

Acid anhydride to ester w/ alcohol

Acid anhydride to ester w/ alkoxide

Acid anhydride to carboxylic acid acid catalyzed

Acid anhydride to carboxylic acid in base

Acid anhydride to amide

R-NH2

Works with ammonia, 1 and 2 amines

Acid anhydride reduction w/ LiAlH4

Acid anhydride reaction w/ excess grignard

Transesterification acid catalyzed

Transesterification base catalyzed

Ester hydrolysis to carboxylic acid acid catalyzed

Ester hydrolysis to carboxylic acid in base

Ester to amide

+ Ammonia —> 1 amide

+ RNH2 —> 2 amide

+ R2NH —> 3 amide

DIBAL reduction

- converts esters into aldehydes

Ester reduction w/ LiAlH4

Removes db O, replaces ester with OH.