ORGO 2 REACTIONS
epoxide reduction
1. LiAlH4 2. H2O forms an OH on one side
How to prepare a primary alc
1. Nucleophilic attack on formaldehyde 2. Nucleophilic attack on ethylene oxide 3. Hydrogenation of an aldehyde 4. NaBH₄ (or LiALH₄) reduction of an aldehyde 5. Hydroboration-oxidation of a terminal alkene
3 reactions to add ethers
1. Williamson Ether Synthesis 2. Acid-Catalyzed Alcohol Condensation 3. Acid-Catalyzed Alkoxyation
How to prepare a tertiary alc
1. grignard addition to a ketone 2. hydration of a geminally substituted alkene
How to prepare a secondary alc
1. reduction/hydrogenation of a ketone 2. grignard addition to an aldehyde
2 ways to make epoxides via epoxidation
1. using peroxy acid (RCO₃H) 2. intramolecular SN2 reaction of halohydrins
Alkoxymercuration of alkenes
2 step reaction similar to oxymercuration reduction but used alcohol as the nucleophile instead of H20 reagents: 1.Hg(OAc)₂, alcohol over 2. reducing agent (ex: 1.Hg(OAc)₂, CH3CH2OH over 2.NaBH₄, NaOH) anti sterochem and mark
Base-Catalyzed Ring Opening
A strong nucleophile attacks the side of the ring that is least substituted Reagents: Nucleophile over proton donor (Ex: NaOH over H₂O: makes anti-vicinal diols. Other examples are KCN, NaSPh, NaN₃) anti, anti mark
Friedel-Crafts Acylation
Acylium cation formation adds acyl group to benzene Reagents: Acyl Cl, AlCl₃ over CS? HCl as another product
Nitration of Benzene
Adds NO₂ to benzene Reagents: HNO₃, H₂SO₄ H₂O as another product
Sulfination of Benzene
Adds SO₃ Reagents: SO₃, H₂SO⁴
Bromination of Benzene
Adds a Br to a benzene Reagents: Br₂ and an iron catalyst over heat (Ex: Br₂ FeBr₃, ∆) Gives HBr as another product Can be used w Cl
Alkyl Cl formation
Adds a Cl to an alkyl group Reagents: Alcohol and SOCl₂ (thionyl chloride) SO₂ and HCl are other products
Friedel-Crafts Alkylation
Adds an alkyl group to benzene Reagents: Alkyl w Cl, AlCl₃ HCl as another product
Electrophilic addition of alkene w X2
Adds one X and makes an ether from an alkene Reagents: X₂ + H₂O or OH⁻ carbonation intermediate, X attaches to least substituted side first anti (ether adds to more substitited position)
How do you prepare organolithium
Alkyl halide reacts with 2Li is diethyl ether to replace to halide with Li Will not work if there is water or oxygen
How do you prepare Grignard reagents
Alkyl halide with Mg in diethyl ether or THF adds Mg inbetweeen the alkyl group and halide
Ozonolysis
An alkene splits in the middle and adds oxygens Reagents: O3 over reducing agent (Ex: O₃ over DMS or H₂O or H₂O₂
Acid-Catalyzed Ring Opening
An epoxide reaction in which the epoxide is protonated and a nucleophile forms on the most substituted side Reagents: H⁺, nucleophile (Ex:HCl or H⁺ over R-OH or H₂O) anti, mark
Swern Oxidation
Another method of bringing an alcohol to an aldehyde or ketone 1) DMSO, (COCl₂), DCM, cold 2) Et₃N
How do you make iodomethylzinc iodide
CH₂I₂ + Zn in diethyl ether over Cu forms ICH₂ZnI used in simmons smith rxn
Oxidizing Alcohol's using Cr6+
Can oxidize completly A primary alc can form a carboxillic acid
Clemmensen Reaction
Carbonyl in ketone or aldehyde is reduced to CH₂ Reagents: Zn(Hg) over HCl
Wolff-Kishner Reaction
Carbonyl is ketone or aldehyde is reduced to CH₂ Reagents: H₂NNH₂, KOH over triethylene glycol, ∆ (H₂O may be used sometimes)
Simmons-Smith Reaction
Cycloproponation: starts with alkene and forms cyclopropane Reagents: CH₂I₂ over Zn(Cu) and diethyl ether (can also use ICH₂ZnI) Stereospecific: cis stays cis, trans stays trans
Diels-Alder Reaction
Diene → cyclohexene Reagents: any dienophile with an electron-withdrawing substituent, heat Cyclic exchange of electrons to form a six-membered ring Will form bridgehead cyclohexene if the diene is a cycloalkene
how to add syn vivincal diols
Dihydroxylation of alkene catalyzed by OsO₄ Reagents: (CH₃)₃COOH, OsO₄ (cat.) over t-BuOH, OH⁻
Convert alcohol to ester
Fisher esterfication
How to prepare an alcohol on the least substituted part of an alkene
Hydroboration oxidation Reagents: 1. BH₃ 2. H₂O₂, OH⁻ syn addition, antimark
Two ways to prepare alcohols from ketones or aldehydes
Hydrogenation or reduction by a hydride source
How to prepare an alcohol on the most substituted part of an alkene
H₂SO₄ (or any H⁺) over H₂O
Halohydrin Formation
Makes an alcohol from an alkene Reactants: X₂, H2O (where X₂=I, Br, Cl) Intermediate: halonium ion Regiochemistry: Markovnikov Stereochemistry: anti addition
weak bases
NH₃ , HCO₃⁻, and CO₃²⁻
The addition-elimination mechanism (Sn2Ar)
Negatively charged molecule adds to a good LG on benzene and makes a Meisenheimer complex intermediate, LG leaves to restore aromaticity Reagents: Benzene w a LG, nucleophile (Ex: Benzene w Cl attached, NH₃ makes an aniline)
Using acyl Cl and anhydride in ester formation
OH⁻ attacks carbonyl carbon, H and Cl leave reagents: pyridine
Oxidizing a Primary Alcohol to an Aldehyde
Only oxidizes once Reagents: PCC or PDC over CH₂Cl₂
Ether cleavage
Only reaction ethers undergo; makes an alkyl halide by protonation of ether followed by SN2 Reagents: HX (or any strong acid?)(Ex:HBr)
Reaction of grignards and organolithiums
React with carbonyl to reduce Reagents: organolithium or Grignard with a carbonyl 1. diethyl ether 2.H₃O⁺
Preparation of acyl chlorides
Reacts a carboxillic acid to make acyl chloride Reagents: Carboxillic acid, SOCl₂ Also produces SO₂ and HCl
Hydrogenation of aldehyde or ketone
Reagents: H₂ or D₂ with Pt or Pd in ethanol
Reduction of aldehyde/ketones
Reagents: NaBH₄ or LiAlH₄ in methanol or diethyl ehter sometimes water
reduction of carboxylic acids
Requires LiAlH₄ to form alcohol
Williamson Ether Sythesis
SN2 of 1° or 0° alkyl halides reagents: salt+O+alkylgroup (ex:NaOEt) (alkoxide) 2° or 3° alkyl halides will favor E2
Acid-Catalyzed Alkoxyation
Same mechanism as acid-catalyzed hydration, but uses alcohol as the nucleophile instead of H₂O Reagents: H⁺ over alcohol (ex:H₂SO₄ over CH₃OH) mark, watch for shifts
Acid-catalyzed conversion of alcohols to ethers (not the sym one)
Similar to hydration where you start with an alkene, H+ adds to the least substituted, then alkoxide or alcohol adds to carbocation and H is deprotonated Reagents: Alcohol, H₂SO₄, ∆ creates an ether and H₂O Carbocation intermediate OH on both ends does an intramolecular reaction
Metal acetylide reaction with a carbonyl
Similar to organolithium and grignard reaction with carbonyl Reagents: metal acetylide and carbonyl 1.NH₃ 2. H₃O⁺ (Ex: sodium acetylide with ketone)
converting OH to Cl
SoCl₂, pyridine
how do you form a bromohydrin?
Start with an alkene and use Br₂ and H₂O anti addition and mark alc
Oxidative cleavage of diols
Turns a diol into a ketone + an aldehyde Reagents: Diol and perioidc acid (HIO₄)
Friedel-Crafts acylation using anhydrides
Two carboxylic acids react to make acetic anhydride which will add an acyl group to benzene Reagents: To form acetic anhydride: 2 carboxylic acids (acetic acid?) To form acyl benzene: acetic anhydride, benzene, AlCl₃ 1 carboxylic acid as another product
Making an epoxide using peroxy acid
addition reaction that adds oxygen to alkene to form an epoxide + a carboxilyc acid reagents: peroxy acid (RCO₃H) (Ex: MCPBA or MMPP) syn addition
Hydrohalogenation
adds a halogen to an alkene reagents:HX (ex:HBr) watch for shifts, mark
How to add hydrocarbons besides Friedel-Crafts
alkene and H₂SO₄ can make a carbocation which adds to benzene
Gilman reagent reactions
alkene next to a carbonyl will add alkyl group on Beta H
Making an epoxide using SN2
alkene reacts with halohydrin to form an epoxide + X⁻ reagents: 1. X₂ over H₂O 2. Base⁻ anti stereochem
bases for E2 zaitsev
all strong bases 2° carbons: RO⁻, RC triple bond C⁻, NH₂⁻, H⁻, ∆ 3° carbons: same as above + OH⁻
how to make an alkyne
can substitute alkyl halide with sodium acetylide
Sharpless Epoxidation
converts allyl alcohols into enantioselective epoxides depending on the tartrate used reagents: oxidizing agent over Ti catalyst and tartrate (Ex: (CH₃)₃OOH over Ti(OCH(CH₃)₂I₄, (-)-DET positive (S,S) attacks above, negative (R,R) attacks below
Carbonation of Grignard Reagents
grignard reagents can react with dry ice (frozen co2 gas) to create carboxylic acids
How do you prepare a Gilman reagent?
in diethyl ether
how to make an alkyne from a terminal alkene
must 1st start with halide addition reagents: Br₂ double dehydrohalogenation reagents: strong base (ex: NaNH₂, ∆)
hydration reaction on an alkene
need water
disulfide formation
oxidation of thiol can form an intramolecular bond if two thiols on a molecule, use O₂ and FeCl₃ as reagents
Hydrogenation of aldehyde forms
primary alcohol
hydrolysis
reaction of an ion with water to produce the conjugate acid and hydroxide ion or the conjugate base and hydrogen ion
benzylic and allylic bromination
reagents: NBS, ∆, (or Br2 and light) sometime benzyl peroxide replaces an H
decarboxylation
removal of CO₂ 1. compound needs at least two carbonyls 2. one carbonyl needs to be a carboxylic acid 3. need to be seperated by 1 carbon 4. need heat
Hydrogenation of ketone forms
secondary alc (if two CH groups)
bluky bases
t-buO⁻ LDA LiTMP
Acid-Catalyzed Alcohol Condensation
takes two smaller molecules and turns it into one ether reagents:H⁺ and ∆ (ex: H3O⁺ over ∆) only forms symmetrical ethers mech: o protonates and the second molecule attacks and water leaves, second h is taken off
adding na to a terminal alkyne
use NaNH₂ over NH₃ usually used for grignard
how do you make OH a really good leaving group
use PBr3
dehydration of an alcohol
use a strong acid (ex: H₂SO₄) makes an alkene
Sulfide reactions
very easily oxidized reagents: NaIO₄, H₂O₂ for partial oxidation, KMnO₄ or H₂O₂ for full oxidation
