UBC CHEM 233 SOLVENTS/REACTANTS MIDTERM 2
QUESTIONS AND CORRECT DETAILED ANSWERS
(VERIFIED ANSWERS) |ALREADY GRADED A+||BRAND
NEW!
LiN(i-Pr(2)) Ans✓✓✓LDA, strong Base
Na-H Ans✓✓✓deprotonates
H and Na dissociate, H becomes negative so it steals an H form another
molecule to make H2
THF, DMSO, DMF Ans✓✓✓aprotic solvents for SN2/E2
K-Otbu Ans✓✓✓E2 strong base
PBr(3) Ans✓✓✓phosphorous tribromide. replaces the OH groups with
Br as leaving groups, inverts stereochemistry.
SOCl(3) Ans✓✓✓replaces OH with Cl for leaving group, inverts
stereochemistry.
TsO-, TsCl-, Ans✓✓✓TOSYLATES: replace OH as leaving group with
ought inverting stereo chemistry.
, H2SO4+ H20 Ans✓✓✓results in H30, used for
alkene addition or
Acetal to aldehyde reaction, and
Ketal to Ketone reaction
H2SO4+ R-OH Ans✓✓✓results in protonated alcohol that can be used
to generate acetal/ketal, form ketones and aldehydes.
H2 + Pt/Pd/Ni Ans✓✓✓Alkyne to alkene to alkane reaction.
Pd/BaSO4, Quinoline, CH3OH, Ans✓✓✓Poison catalyst
Lindlårs catalyst
Alkyne to Z alkene
Na/Li + NH3 Ans✓✓✓Alkyne to E Alkene
NaBH4 + protic solvent Ans✓✓✓weak base, used for reduction
Ketone to (secondary) OH
Aldehyde to (primary) OH
does not react with ester or carboxylic acid
QUESTIONS AND CORRECT DETAILED ANSWERS
(VERIFIED ANSWERS) |ALREADY GRADED A+||BRAND
NEW!
LiN(i-Pr(2)) Ans✓✓✓LDA, strong Base
Na-H Ans✓✓✓deprotonates
H and Na dissociate, H becomes negative so it steals an H form another
molecule to make H2
THF, DMSO, DMF Ans✓✓✓aprotic solvents for SN2/E2
K-Otbu Ans✓✓✓E2 strong base
PBr(3) Ans✓✓✓phosphorous tribromide. replaces the OH groups with
Br as leaving groups, inverts stereochemistry.
SOCl(3) Ans✓✓✓replaces OH with Cl for leaving group, inverts
stereochemistry.
TsO-, TsCl-, Ans✓✓✓TOSYLATES: replace OH as leaving group with
ought inverting stereo chemistry.
, H2SO4+ H20 Ans✓✓✓results in H30, used for
alkene addition or
Acetal to aldehyde reaction, and
Ketal to Ketone reaction
H2SO4+ R-OH Ans✓✓✓results in protonated alcohol that can be used
to generate acetal/ketal, form ketones and aldehydes.
H2 + Pt/Pd/Ni Ans✓✓✓Alkyne to alkene to alkane reaction.
Pd/BaSO4, Quinoline, CH3OH, Ans✓✓✓Poison catalyst
Lindlårs catalyst
Alkyne to Z alkene
Na/Li + NH3 Ans✓✓✓Alkyne to E Alkene
NaBH4 + protic solvent Ans✓✓✓weak base, used for reduction
Ketone to (secondary) OH
Aldehyde to (primary) OH
does not react with ester or carboxylic acid
