Organic Synthesis Flashcards
What mechanism do alkanes undergo?
free radical substitution
What mechanism do alkenes undergo?
electrophilic addition
What mechanism do alcohols and haloalkanes undergo?
nucleophilic substitution
alkane –> haloalkane
reagent: halogen
conditions: UV light
reaction: free radical substitution
alkene –> alkane
reagent: H2(g)
conditions: Ni catalyst/423K (high temp)
reaction: addition/hydrogenation
alkene –> haloalkane
reagent: halogen OR hydrogen halide
conditions: room temperature
reaction: electrophilic addition/halogenation
alkene –> alcohol
reagent: H20(g)
conditions: H3PO4 catalyst
reaction: electrophilic addition/hydration
1° alcohol –> aldehyde
reagent: K2Cr2O7
conditions: dilute H2SO4/heat and distil
reaction: oxidation
1° alcohol –> carboxylic acid
reagent: K2Cr2O7
conditions: dilute H2SO4/heat under reflux
reaction: oxidation
2° alcohol –> ketone
reagent: K2Cr2O7
conditions: dilute H2SO4/heat under reflux
reaction: oxidation
alcohol –> alkene
conditions: conc H2SO4 or H3PO4
reaction: elimination/dehydration
alcohol –> haloalkane
reagent: hydrogen halide made in situ
NaX + H2SO4 –> HX + NaHSO4
conditions: heat under reflux
reaction: nucleophilic substitution
1° haloalkane –> alcohol
reagent: NaOH(aq) or H2O(aq)
conditions: heat under reflux
reaction: nucleophilic substitution/hydrolysis (if water in used as a nucleophile)
what mechanisms do aromatic compounds undergo?
electrophilic substitution
2,4,6 directing groups
activating groups:
NH2
OH
3,5 directing groups
deactivating groups:
NO2
aldehyde –> 1° alcohol
reagents: NaBH4(aq)
reaction: nucleophilic addition
ketone –> 2° alcohol
reagents: NaBH4(aq)
reaction: nucleophilic addition
carbonyl –> hydroxynitrile
reagents: 2NaCN + H2SO4 –> 2HCN + Na2SO4 (in situ)
reaction: nucleophilic addition
what reactions do carboxylic acids undergo?
- redox (with metals)
- neutralisation (with bases)
- forms carboxylate ions and salts
carboxylic acid + metal
–> metal carboxylate + hydrogen
butanoic acid + Mg –> magnesium butanoate + H2
carboxylic acid + metal oxide
–> metal carboxylate + water
butanoic acid + CaO –> calcium butanoate + H2O
carboxylic acid + alkali
–> carboxylate salt + water
butanoic acid + NaOH –> sodium butanoate + H2O
carboxylic acid + metal carbonate
–> carboxylate salt + carbon dioxide + water
butanoic acid + MgCO3 –> magnesium butanoate + CO2 + H2O
carboxylic acid –> acid anhydride
two carboxylic acids undergo condensation reaction (one OH group removed and the H from the other OH group)
esterification
carboxylic acid + alcohol –> ester
(alcohol-yl carboxylic acid-oate)
heat under reflux with conc H2SO4
acid hydrolysis of esters
ester + water –> carboxylic acid + alcohol
heat with a dilute aqueous acid
alkaline hydrolysis of esters
ester + alkali –> carboxylate salt + alcohol
IRREVERSIBLE
carboxylic acid –> acyl chloride
carboxylic acid + SOCl2 (thionyl chloride) –> acyl chloride + SO2(g) + HCl(g)
propanoic acid + SOCl2 –> propanoyl chloride
(more reactive than carboxylic acids)
acyl chloride –> ester
acyl chloride + alcohol –> ester + HCl
ethanoyl chloride + methanol –> methyl ethanoate + HCl
acyl chloride –> carboxylic acid
acyl chloride + water –> carboxylic acid + HCl
ethanoyl chloride + water –> ethanoic acid + HCl
acyl chloride –> 1° amide
acyl chloride + ammonia –> primary amide + ammonium chloride
ethanoyl chloride + 2NH3 –> ethanamide + NH4Cl
(can form a 2° and 3° amide by reacting with 1° and 2° amines)
acid anhydride –> carboxylic acid
acid anhydride + alcohol –> carboxylic acid + ester
