Organic Reactions Flashcards
Alkene to Alkane
Type of reaction - reagents - conditions
Addition - H2 (g), Ni catalyst, 150 degrees
Alkane to CO2 and H2O
Type of reaction - reagents - conditions
complete combustion - N/A - excess oxygen
Alkane to halogneoalkane Type of reaction - reagents - conditions
Free radical substitution - halogen gas - UV light
Halogenoalkane to alkene
Type of reaction - reagents - conditions
Elimination - ethanolic NaOH - reflux
Alkene to halogenoalkane Type of reaction - reagents - conditions
Electrophilic substitution - X-H - N/A
Alkene to Dihalogenoalkane Type of reaction - reagents - conditions
Electrophilic addition - X2 - N/A
Alkene to alcohol
Type of reaction - reagents - conditions
Electrophilic addition - stream, conc H3PO4 - 100 degrees (for steam)
Alcohol to Alkene (2 methods)
Type of reaction - reagents - conditions
- Elimination - conc. H3PO4 - 180. degrees
- Elimination - Al2O3 - heat
Alkene to diol
Type of reaction - reagents - conditions
N/A - acidified potassium permanganate (KMnO4) - N/A
Alkane to Alkene (2 types)
Type of reaction - products - conditions
- Thermal Cracking - Alkenes and alkanes - 400 < T < 900, 7000 kPa
- Catalytic Cracking - branched alkanes, cycloalkanes and aromatic hydrocarbons - zeolite catalyst, 450, slight pressure
Halogenoalkane to grignard reagent
Type of reaction - reagents - conditions
N/A - Mg in dry ether - reflux
Halogenoalkane to 1 amine
Type of reaction - reagents - conditions
Nucleophilic substitution - XS NH3 in ethanol - sealed tube, heat
Halogenoalkane to nitrile
Type of reaction - reagents - conditions
Nuc Sub - aq/ethanolic mix of KCN - reflux
Nitrile to carboxylic acid (2 ways)
Type of reaction - reagents - conditions
- Hydrolysis - Dilute HCl - reflux
- Hydrolysis - aq NaOH then acid - reflux
Nitrile to 1 amine (2 ways)
Type of reaction - reagents - conditions
- Reduction - LiAlH4 in dry ether - N/A
- Reduction - H2 - Ni, 150
Halogenoalkane to Alcohol
Type of reaction - reagents - conditions
Nuc sub - aqueous NaOH or KOH - warm
Alcohol to Halogenoalkane
Type of reaction - reagents - conditions
- Chlorination - PCl5 - room temp
- Bromination - 50% conc H2SO4, KBr - reflux
- Iodination - damp red P, I2 - warm
Alcohol to acid/ aldehyde/ ketone
Type of reaction - reagents - conditions
Oxidation- acidified K2Cr2O7 - reflux or distill depending on required product
Ketone/ aldehyde/ acid to alcohol
Type of reaction - reagents - conditions
Reduction - LiAlH4 in dry ether - N/A
What can LiAlH4 reduce and what are the conditions for its use
Polar double bonds - dry ether
Alcohol to ester
Type of reaction - reagents - conditions
Condensation (esterification) - carboxylic acid, conc H2SO4 - reflux
Ester hydrolysis in acid
Type of reaction - reagents - conditions - products
Hydrolysis - water, HCl - reflux - equilibrium mix of ester, acid and alcohol
Ester hydrolysis in alkali
Type of reaction - reagents - conditions - products
Hydrolysis - water, NaOH - reflux - carboxylate ion and alcohol
Acid to acyl chloride
Type of reaction - reagents - conditions - other products
Substitution - PCl5 - N/A - POCl3 + HCl
Acyl chloride to carboxylic acid
Type of reaction - reagents - conditions
Nucleophilic addition elimination - water - N/A
Acyl chloride to ester
Type of reaction - reagents - conditions
Nucleophilic addition elimination
- alcohol - anhydrous
Acyl chloride to amide (primary)
Type of reaction - reagents - conditions
Nucleophilic addition elimination
- ammonia - N/A
Acyl chloride to secondary amide
Type of reaction - reagents - conditions
Nucleophilic addition elimination- primary amine - N/A
Describe the first and second steps of Nucleophilic addition elimination of water and ethanoyl chloride
- Lone pair on O attacks delta+ C and double bond breaks with electrons going to O (addition)
- H lost from OH2 group, double bond reforms and Cl eliminated (elimination)
How are polyesters formed (3 ways)
Type of reaction - reagents - conditions
Polymerisation - diol, dicarboxylic acid- reflux, H2SO4
Polymerisation - diol, diacyl chloride - N/A
Polymerisation - hydroxyl group and a carboxylic acid group on either end of the molecule
Why are ester polymers biodegradable
The ester linkage is susceptible to hydrolysis
Two reactants to make polyamides
Diamine and dicarboxylic acid
3 pieces of evidence against the kekule structure
- All bond lengths are the same
- Enthalpy of hydrogenation is a less negative value than expected if it was 3 double bonds
- Benzene doesn’t undergo addition reactions
What species attacks benzene rings
Electrophile
Why don’t benzene react via addition
As they don’t want to lose the stability of the delocalised ring
How to form a nitro group
Type of reaction - reactants - how both reaction steps happen
Acid base - nitric acid and sulphuric acid
1. Nitric acid acts as base and H2NO3+ forms
2. Dissociation into water and nitronium ion
Benzene to Nitrobenzene
Type of reaction - reactants - conditions
Electrophilic substitution - nitric acid and benzene - 50 degrees and conc. H2SO4
Why is nitration of benzene done at 50 degrees
Higher gives multiple substitutions and lower reduces rate of reaction too much
What’s the electrophile in friedel-crafts acylation
Acylium ion
How is an acylium ion formed
Acyl chloride + AlCl3 —> AlCl4- + acyclium ion
Acyl group substitution onto benzene ring
Type of reaction - reactants - conditions
Electrophilic substitution - acyl chloride, AlCl3 - anhydrous
Bromination of benzene
Type of reaction - reactants - conditions
Electrophilic substitution - Br2, FeBr3 catalyst, - catalyst made in situ from bromine and iron filings
How is the catalyst formed in bromination of benzene
Reactants and equation
Iron fillings and bromine
2Fe + 3Br2 —> 2FeBr3
What’s the Electrophile in Bromination of benzene
Bromonium Br+
What kind of group is the OH in phenol and why
(2,4,6) Activating - adds electron density to the ring (lone pair on O is involved in the aromatic delocalisation system)
Phenol + bromine water
Characteristics of product
2,4,6-tribromophenol - white ppt with antiseptic smell
Phenol nitration
Type of reaction - reactants - conditions
Electrophilic substitution - dilute nitric acid - 50 degrees in concentrated sulfuric acid
How do phenols behave differently to alcohols
They are weak acids (less so than carboxylic acids) and don’t undergo Nucleophilic substitution reactions
Why can phenol behave as an acid
Delocalisation from the ring can stabilises A-
How is friedelcrafts alkylation different to acylation
A Halogenoalkane is used rather than an acyl chloride
