lab final Flashcards
oxidation of unknown alcohol:
starting material
unknown secondary alcohol
oxidation of unknown alcohol:
oxidizing agent
sodium hypochlorite (NaOCl) —> hypochlorous acid (HOCl)
oxidation of unknown alcohol:
solvent
acetic acid (CH3CO2H)
oxidation of unknown alcohol:
product
ketone
oxidation of unknown alcohol:
line reaction regents
5% NaOCl, CH3CO2H 0 C
oxidation of unknown alcohol:
testing for excess hypochlorite
if the KI-starch paper turned blue when coming into contact with the reaction solution, there was excess hypochlorite in solution = move onto quenching
if it remained white, add extra NaOCl until the paper turned blue
oxidation of unknown alcohol:
reaction quenching agent
sodium bisulfite used to quench excess hypochlorite remaining after the reaction has gone to completion
oxidation of unknown alcohol:
reaction quenching and KI-starch paper
used to check the progress of the quenching process
checking to ensure the paper remained white instead of turning blue
what is quenching?
forcing any residual oxidizer to react, stopping the reaction
oxidation of unknown alcohol:
basification reagent
6M sodium hydroxide
oxidation of unknown alcohol:
basification process
after the reaction was complete, 6M sodium hydroxide was added to achieve a basic solution
the base neutralized the residual acetic acid (forming acetate) allowed it to be water soluble while the product remained un-ionized
oxidation of unknown alcohol:
extraction reagent used
methylene chloride
oxidation of unknown alcohol:
extraction process
methylene chloride (denser than water) was used to extract the product into the organic layer (bottom) using a separatory funnel
organic layer was collected and washed with deionized water and brine (to remove excess water)
oxidation of unknown alcohol:
drying agent and how it was removed
organic layer dried with magnesium sulfate (MgSO4) and removed via gravity filtration
oxidation of unknown alcohol:
reagent in line reaction using common names
bleach, acetic acid
conversion of carvone to carvacrol:
starting material
(R)-(-) carvone
conversion of carvone to carvacrol:
catalyst/solvent
6M H2SO4
conversion of carvone to carvacrol:
product
carvacrol
conversion of carvone to carvacrol:
what does the reaction do?
converts a chiral compound to an achiral compound through an acid-catalyzed elimination
conversion of carvone to carvacrol:
reagents on line reaction
H2SO4, heat
conversion of carvone to carvacrol:
what is the reaction driven by?
aromaticity
what is reflux?
boiling a reaction without losing solvent
conversion of carvone to carvacrol:
extraction reagent used
after reflux, the product was transferred to a separatory funnel and extracted into diethyl ether and washed with brine
conversion of carvone to carvacrol:
basification reagent
ether extract was washed with sodium bicarbonate (NaHCO3) to neutralize the acid
conversion of carvone to carvacrol:
drying agent and removal
ether dried with sodium sulfate (Na2SO4) and removed via suction filtration
conversion of carvone to carvacrol:
ether removal
evaporation
Williamson ether synthesis (microwave edition):
occurs under what conditions?
what type of alkyl halides are used?
what kind of reaction?
basic
primary
SN2
Williamson ether synthesis (microwave edition):
starting materials
4-bromophenol and unknown aldehyde
Williamson ether synthesis (microwave edition):
catalysts
tetra-N-butylammonium bromide (TBAB) = phase transfer catalyst
KOH = base catalyst
Williamson ether synthesis (microwave edition):
solvent
water
Williamson ether synthesis (microwave edition):
product
ether
Williamson ether synthesis (microwave edition):
how does TBAB work as a phase-transfer catalyst?
helps ions cross between the organic and aqueous phase
what is microwave reflux?
a technique that heats reactions without losing solvent
speed up reaction times by holding reaction at constant temperature and pressure
Williamson ether synthesis (microwave edition):
extraction reagents used
diethyl ether and water
Williamson ether synthesis (microwave edition):
basification reagent
potassium hydroxide
Williamson ether synthesis (microwave edition):
drying reagent and removal
sodium sulfate and removed via gravity filtration
Williamson ether synthesis (microwave edition):
purification method
gas chromatography
GC separates components of a mixture to what scale?
milligram-to-gram
GC mobile phase
polarity?
methylene chloride (DCM)
less polar
GC stationary phase
polarity?
silica gel
more polar
Williamson ether synthesis (microwave edition):
mobile phase
product of this reaction will remain in the mobile phase because it is less polar than the highly polar stationary phase
Williamson ether synthesis (microwave edition):
stationary phase
residual polar impurities from this reaction bind to silica gel and do not get collected
Williamson ether synthesis (microwave edition):
removal of excess solvent
hot plate with a snorkel
TLC stationary phase
polarity?
silica gel
polar compounds bind to silica gel and do not migrate up the plate
TLC mobile phase
polarity?
methylene chloride
less polar compounds remain in the mobile phase and migrate up the plate with the solvent front
TLC Rf calculation
distance from origin to spot/distance from origin to solvent front
acid v.s base nucleophilic ring opening of 1,2-epoxyhexane:
acidic cleavage vs basic cleavage
stereochemistry
acid: nucleophile attacks more sub side
base: nucleophile attacks less sub side
stereochem: anti addition
acid v.s base nucleophilic ring opening of 1,2-epoxyhexane:
starting material
1,2-epoxyhexane
acid v.s base nucleophilic ring opening of 1,2-epoxyhexane:
acid catalyst
base catalyst
acid: sulfuric acid (H2SO4)
base: sodium methoxide (NaOCH3)
acid v.s base nucleophilic ring opening of 1,2-epoxyhexane:
solvent
methanol (CH3OH)
acid v.s base nucleophilic ring opening of 1,2-epoxyhexane:
acid reagents on line reaction
base reagents on line reaction
acid:
H2SO4, methanol
base:
1. NaOCH3, methanol
2. NH4Cl
acid v.s base nucleophilic ring opening of 1,2-epoxyhexane:
acidic: washed with ___ to neutralize
basic: washed with ___ to neutralize
acid: saturated sodium bicarbonate
base: saturated ammonium chloride
acid v.s base nucleophilic ring opening of 1,2-epoxyhexane:
drying agent and removed via
magnesium sulfate removed via decating
acid v.s base nucleophilic ring opening of 1,2-epoxyhexane:
removal of excess ether
rotary evaporator
GC mixture is separated based on each component’s affinity for the ___phase vs the ___ phase
each component will exit the column ____
non-polar stationary phase vs the inert gas mobile phase
at different retention times
GC % of each component calculation
(A1/ (A1 + A2 + A3 )) x 100
Fischer esterification (microwave edition):
starting materials
acetic acid and unknown primary alcohol
Fischer esterification (microwave edition):
catalyst
sulfuric acid (H2SO4)
Fischer esterification (microwave edition):
solvent
acetic acid (CH3CO2H)
Fischer esterification (microwave edition):
products
ester and H20
Fischer esterification (microwave edition):
how to drive the reaction’s equilibrium toward the formation of the products
Le Chatlier’s principle:
-increase concentration of reactants
-decrease concentration of products (remove water easiest)
Fischer esterification (microwave edition):
extraction reagents
washed with water and then with 5% sodium bicarbonate solution
Fischer esterification (microwave edition):
basification reagent
formed what?
sodium bicarbonate to neutralize the organic layer resulting in the formation of CO2 that bubbled out of solution
then final brine wash
Fischer esterification (microwave edition):
drying agent and removal
sodium sulfate (Na2SO4) removed via decanting
amide synthesis:
starting materials
acetic anhydride and unknown primary amine
amide synthesis:
catalyst
provides what?
aluminum oxide (Al2O3)
a basic polar surface for the reaction to take place on while also neutralizing acetic acid byproduct as it forms
amide synthesis:
solvent
acetic anhydride ((CH3CO)2O)
amide synthesis:
products
amide and acetate
amide synthesis:
line reaction reagent
solid Al2O3
amide synthesis:
using aluminum oxide allows for?
admiration of a carboxylic acid in high yields without having to use an acid halide
amide synthesis:
isolation method
solid/liquid extraction
amide synthesis:
extraction reagent
ethyl acetate
reduction of an unknown aldehyde/ketone (microwave edition):
starting material
unknown ketone/aldehyde
reduction of an unknown aldehyde/ketone (microwave edition):
reducing agent
also acts as?
sodium borohydride (NaBH4)
nucleophile
reduction of an unknown aldehyde/ketone (microwave edition):
solvent
95% ethanol
reduction of an unknown aldehyde/ketone (microwave edition):
product
primary or secondary alcohol
reduction of an unknown aldehyde/ketone (microwave edition):
line reaction reagents
- NaBH4, 95% ethanol
- H20
reduction of an unknown aldehyde/ketone (microwave edition):
extraction regent used
methylene chloride
reduction of an unknown aldehyde/ketone (microwave edition):
drying agent and removal
magnesium sulfate removed via filtration
Wittig Reaction:
starting materials
benzyltriphenylphosphonium chloride (slide) and 9-anthraldehyde
Wittig Reaction:
solvent
methylene chloride (CH2Cl2)
Wittig Reaction:
products
9-(2-phenylethenyl)anthracene and O=PPh3
Wittig Reaction:
line reaction reagents
NaOH, CH2Cl2
then
CH2Cl2
Wittig Reaction:
basification reagent
sodium hydroxide added dropwise resulting in formation of ylide
Wittig Reaction:
reaction mixture is non-homogenous as the aldehyde is ____ and the ylide is ___
hydrophobic, hydrophilic
Wittig Reaction:
-what is major product?
-what type of alkyl halides are best for making ylides?
-E
-primary
Wittig Reaction:
drying agent and removal
calcium chloride (CaCl2) removed via decanting
Wittig Reaction:
simple distillation did what?
removed methylene chloride
Wittig Reaction:
product was purified how?
recrystallization
aldol condensation:
starting materials
acetone (Nu-) and 2 eq unknown aldehyde (E+)
aldol condensation:
solvent
95% ethanol
aldol condensation:
product (prefers what stereochem?)
a/B-unsaturated ketone (prefers E)
aldol condensation:
how is sodium hydroxide added?
dropwise
aldol condensation:
line reaction reagents
aq NaOH, 95% ethanol
aldol condensation:
isolation methods
crystallization and recrystallization
aldol condensation:
crystals washed with what?
sodium hydroxide to neutralize
aldol condensation:
recrystallization used for what?
purification