108963-97-9Relevant articles and documents
A Novel Synthesis of L-Pyroglutamic Acid Derivatives from L-Proline: Utility of N-Protecting Groups for Ruthenium Tetroxide Oxidation of Cyclic α-Amino Acids
Yoshifuji,Shigeyuki,Tanaka, Ken-ichi,Kawai, Tomoyuki,Nitta, Yoshihiro
, p. 3873 - 3878 (2007/10/02)
The utility of four urethane type N-protecting groups, benzyloxycarbonyl (Z), p-nitrobenzyloxycarbonyl , trichloroethoxycarbonyl (Troc) and tert-butoxycarbonyl (Boc) groups, was tested in the ruthenium tetroxide (RuO4) oxidation of N-protected L-proline esters.Three groups, but not the Z group, which was decomposed by RuO4, were found to be stable during the oxidation and afforded high yields of the corresponding L-pyroglutamic acid esters.Removal of the protecting groups from the oxidation products was carried out successfully in the usual manner to give N-unsubstituted (NH-type) L-pyroglutamic acid derivatives without racemization.The first transformation of L-proline into L-pyroglutamic acid and its derivatives has been accomplished.Keywords - oxidation; ruthenium tetroxide oxidation; lactam synthesis; L-pyroglutamic acid synthesis; carboxamide N-protection; ruthenium tetroxide; L-proline; L-pyroglutamic acid; twophase method.