Selective tert-butyl ester deprotection in the presence of acid labile protecting groups with use of ZnBr2.
Chemoselective hydrolysis of tert-butyl esters in the presence of other acid-labile groups has been explored by employing alpha-amino esters and ZnBr(2) in DCM. Although N-Boc and N-trityl groups were found to be labile, PhF protected amines were compatible with these Lewis acid deprotection conditions such that a variety of N-(PhF)amino acids were prepared in good yields from their corresponding tert-butyl esters.
Kaul
Ramesh
R
Département de chimie, Université de Montréal, C.P. 6128, Succursale Centre Ville, Montréal, Québec, Canada H3C 3JC.
Brouillette
Yann
Y
Sajjadi
Zohreh
Z
Hansford
Karl A
KA
Lubell
William D
WD
D000596:Amino Acids / Q000032:analysis / Q000138:chemical synthesis*; D001965:Bromides / Q000737:chemistry*; D002073:Butanes / Q000737:chemistry; D002384:Catalysis; D004952:Esters / Q000737:chemistry; D007202:Indicators and Reagents; D015394:Molecular Structure; D017967:Zinc Compounds / Q000737:chemistry*
D000596:Amino Acids; D001965:Bromides; D002073:Butanes; D004952:Esters; D007202:Indicators and Reagents; D017967:Zinc Compounds; C093802:zinc bromide