Organic Chemistry II - Final Exam

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What are the alkane reactions?

Free-radical halogenation

What are the reagents in free-radical halogenation?

Cl2/hv, Br2/hv

What are the products of free-radical halogenation?

alkyl chlorides/bromides

What are the alkene reactions?

electrophilic additions, halogenations, hydrogenation, epoxidation, oxidative cleavage

What encompasses an electrophilic addition reaction?

H-X (HBr, HCl, HI)- markovnikov
H-Br with peroxides (ROOR) - anti-markovnikov

H2O/H2SO4 (acid-catalyzed hydration) - marovnikov alcohol

Hg(OAc)2/H2O then NaBH4 - oxymercuration demurcuration: markovnikov, with no rearrangements

BH3 THF then H2O2/OH- = hydroboration-oxidation (antimarkovnikov alcohol)

What encompasses a halogenation?

Br2 or Cl2 in inert solvent - vicinal dihalide

Br2/H2O - halohydrin

What encompasses a hydrogenation?

H2, Pd/C or Pt - syn addition

What encompasses an epoxidation?

mCPBA - epoxide

peracids in general

What encompasses an oxidative cleavage?

O3 then DMS - ozonolysis

KMnO4 (hot, conc) - cleavage into acids/ketones

What are the alkyne reactions?

deprotonation with NaNH2 (generation of acetylide)

addition of H-X (1 or 2 equivalents)

Br2 or Cl2 (1 or 2 equivalents)

HgSO4/H2SO4 - ketone (markovnikov)

BH3 then H2O2/OH- = aldehyde (anti-markovnikov)

H2, lindlar catalyst - cis alkene

Na(s)/NH3 (I) - trans alkene

Reaction with alkyl halides via SN2 (from acetylide anions)

What is involved in an SN2 reaction?

strong nucleophiles

works best with: primary>secondary>tertiary halides

What constitutes a strong nucleophile?

OH-, OR-, CN-, N3-, I-, HS-, RS-

What works best with SN1 reaction?

weak nucleophiles

works best with: tertiary> secondary

Needs carbocation rearrangement if possible

What are examples of weak nucleophiles?

H2O, ROH

What works best with E2 reaction?

strong bases

anti-periplanar requirement

Zaitsev vs. Hofmann rules

What are examples of strong bases?

OH-, OR-, t-BuOK`

What is Zaitsev rule?

What is Hoffman rule?

What works best with E1 reaction?

weak bases

rearrangements if possible

often accompanies SN1 reactions

What are examples of weak bases?

water, alcohols

How can you form an alcohol?

Hydration of alkenes (acid-catalyzed or oxymercuration)

hydroboration - oxidation

reduction of carbonyls with NaBH4 or LiAlH4

Grignard addition: RMgBr + carbonyl → alcohol

What are the reactions within alcohol chemistry?

HX → alkyl halides (SN2 or SN2)

SOCl2 → alkyl chlorides

PBr3 → alkyl bromides

Jones (CrO3/H2SO4)

PCC → controlled oxidation

H2SO4 (heat) → elimination to form alkenes

Tosylation (TsCl, pyridine)

What are the nucleophilic addition reactions?

Hydride reaction: NaBH4, LiAlH4

Grignard reagents (RMgBr)

Organolithium (RLi)

Cyanohydrin formation: HCN

Hydrates: H2O

Acetals: ROH, acid

Imines/enamines: primary and secondary amines, acid catalyst

What to use/do regarding Carboxylic acid derivatives?

acid chloride: SOCl2

Anhydrides: acid chloride + carboxylate

esters: fischer esterification (ROH+H’)

Amides: R-NH2 with acid chloride

Hydrolysis: H3O+ or OH-

Reduction: LiAlH4 → alcohols

What to know regarding aldol reactions?

reactants:

aldol addition product → B-hydroxy carbonyl

aldol condensation → a,B-unsaturated carbonyl (requires heat)

What to know regarding Claisen condensation reactions?

reactants: esters + strong base (matching alkoxide)

aldol addition product → a-hydrogen

aldol condensation →B-keto ester

Intramolecular variant = dieckmann condensation

Michael Addition info

nucleophile adds to B-carbon of a,b-unsaturated carbonyl

reagents: enolate nucleophiles, gilman reagents (R2CuLi)

Acetoacetic ester & malonic ester synthesis

a-alkylation

hydrolysis and decarboxylation

products: substituted ketones (acetoacetic) or substitued carboxylic acids (malonic)

Electrophilic aromatic substitution (EAS)

nitration: HNO3/H2SO4

sulfonation: SO3/H2SO4

halogenation: Br2/FeBr3, Cl2,/FeCl3

friedel-crafts alyklation: R-CL/ALCL3

friedel-crafts acylation: RCOCl/AlCl3

What are the directing effects?

Ortho/para directors: alkyl, OH, OR, NR2, halogens

Meta directors: NO2, SO3H, CN, carbonyls

What are the radical reactions?

radical halogenation

allylic bromination (NBS)

radical polymerization

radical reductions (Bu3SnH, AIBN - classical examples)

What to know from spectroscopy?

IR: carbonyls, alcohols, amines, aromatics

NMR: chemical shifts of all functional groups

MS: fragmentation patterns

Special named reactions

aldol & claisen

diels-alder

wittig reaction (ylides → alkenes)

grignard additions

acetal formation/protection

What are the oxidizing agents?

PCC

Jones (CrO3/H2SO4)

KMnO4 (cold vs. hot)

O3 (ozonolysis)

What are the reducing agents?

NaBH4

LiAlH4

H2,Pd/C

Lindlar

Na/NH3

What are the bases & nucleophiles

NaOH, KOH

NaOEt, NaOMe

t-BuOK

NaNH2

CN-, N3-, OR-, SR-

What are the acid catalysts?

H2SO4

H3PO4

TsOH

HCl, HBr, HI