The hydrolysis of primary amide groups in Asn/Gln-containing peptides

Asymmetric Synthesis of (2S,3R)-Capreomycidine and the Total Synthesis of Capreomycin IB

“…In an attempt to make our approach to capreomycin IB as convergent as possible, the previously reported dipeptide fragment of asparagine and alanine ( 19 ) was prepared . Coupling of tripeptide 18 and 19 with diisopropylcarbodiimide and HOBt resulted in an 88% yield of pentapeptide 20 (Scheme ).…”

Expedient Preparation of All Isomers of 2-Aminocyclobutanecarboxylic Acid in Enantiomerically Pure Form

“…This highly gratifying result warrants further comment. First, while an N -Boc group is generally reputed to be stable in basic medium, the entirely chemoselective alkaline hydrolysis of a primary carboxamide in the presence of a tert -butyl carbamate is noteworthy, since this operation is not often encountered in the literature . Furthermore, no trace of (±)- cis - 2 was detected at any time, and it was verified in a separate control reaction that (±)- cis - 2 is completely stable in the basic reaction conditions.…”

Synthesis and medicinal chemistry of selected antitubercular natural products and natural product derivatives

“…In an attempt to make the synthesis of capreomycin IB 340 as convergent as possible, the dipeptide fragment of asparagines and alanine 359 was prepared. 181 Coupling of tripeptide 356 and 357 with diisopropyl carbodiimide and HOBt resulted in pentapeptide 358, (Scheme 56). Hofmann rearrangement of 358 with bis(triuoroacetoxy)iodosobenzene and pyridine provided the primary amine 359.…”