Protecting Group Flashcards
1
Q
Create Methyl ester
//
Cleavage Methyl ester
A
CH2N2 or TMSCHN2, MeOH, C6H6 or MeOH, H2SO4 // LiOH, MeOH, 5 oC Pig liver esterase (PLE)
2
Q
Cleavage t-butyl ester /// Benzyl ester cleavage /// Phenyl ester cleavage
A
CF3COOH, CH2Cl2 or Bromocatechol borane /// H2, Pd-C or BCl3, DCM /// H2O2, H2O, DMF
3
Q
How to protect amine? /// Cleavage of methyl carbamate /// Cleavage of 9-fluoromethyl carbamate
A
Formation of carbamate or allyl, trityl, benzyl amines. Use with base /// TMSI, DCM or MeLi, THF /// amine base or Bu4+F-, DMF or Bu4+F-, n-C8H17SH
4
Q
Alkyne protecting group
A
By trialkylsilylakyne
Alkyne + Li or Mg, then –> + R3SiX
Cleavage: KF, MeOH, 50 oC or AgNO3, 2,6-lutidine or K2CO3, MeOH or TBAF (can use o-nitrophenol to modify basicity of TBAF)
