21 Cards in this Set
| Front | Back |
|---|---|
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what is the predominant isomer created of hydrobenzoin?
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1R, 2S (meso)
|
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what is the intermediate borate ester hydrolyzed with?
|
water
|
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difference in solvent between LAH and NaBH4?
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NaBH4 can be used with protic solvents, LAH is usually used with ether
|
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why is benzil used in this experiment?
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because it is yellow and we can follow the reduction reaction
|
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what is the melting point of the predominant meso isomer?
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137-139 degrees C
|
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what is the melting point of the racemic mixture of hydrobenzoin?
|
120 degrees
|
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how do we separate the racemic mixture?
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by forming diasteromeric salts
|
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2 differences in the diastereomeric salts
|
1. melting point
2. specific rotation
|
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what is used to resolve the enantiomeric mixture?
|
chiral acid chloride
|
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what is the primary objective of this experiment?
|
reduce benzil to hydrobenzoin using sodium borohydride
|
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what does NaBH4 reduce?
|
aldehydes and ketones
|
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name 3 solvents that NaBH4 can be used in
|
water, ethanol, methanol
|
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what is NaBH4 INSOLUBLE in?
|
ether
|
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name 2 solvents that LAH can be used in?
|
THF or ether
|
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what is LAH INSOLUBLE in?
|
methanol and ethanol
|
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what does LAH create when it reacts violently with H20?
|
metal hydroxides, H2 gas
|
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what does dibal - H reduce?
|
esters and nitriles to aldehydes
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name 7 things that a catalytic H2 reduction will reduce
|
alkynes, alkenes, amides, imines, nitro groups, ketones, and aldehydes
|
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what solvent did we use in this experiment?
|
ethanol
|
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what two things are required to hydrolyze the borate ester into the secondary alcohol?
|
water and heat
|
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3 other reasons benzil is used in this experiment
|
1. compatible with alcoholic solvents
2. stereoselectivity
3. product formed - alcohols
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CHEM 334: Final Exam