The present invention relates to a compound of the formula: ##STR1## wherein R.sub.1 and Q are independently an optionally esterified or amidated carboxyl group; R.sub.2 is hydrogen, an acyl group or an optionally substituted hydrocarbon residue; X is a divalent hydrocarbon residue which may be substituted; or a salt thereof, which is useful as prophylactic and therapeutic agents of bone diseases and as agents for inhibiting thiol protease.
Approaches to the synthesis of endothiopeptides: Synthesis of a thioamide-containing C-terminal bombesin nonapeptide
作者:Jurjus Jurayj、Mark Cushman
DOI:10.1016/s0040-4020(01)89436-9
日期:——
Several approaches have been investigated for the synthesis of a bombesin C-terminal nonapeptide analogue AsnGlnTrpAlaVAlGlyHisLeu-ψCSNHMet-NH2. A new activated dithioester 16 has been synthesized. Thioacylation of methionine methyl ester with 16 was always accompanied by racemization, resulting in the formation of diastereomeric mixtures of reaction products.
Modular Ligands Derived from Amino Acids for the Enantioselective Addition of Organozinc Reagents to Aldehydes
作者:Meaghan L. Richmond、Christopher T. Seto
DOI:10.1021/jo0349375
日期:2003.9.1
series of modularchiralligands that are derived from aminoacids were prepared and tested for their ability to catalyze the asymmetric addition of alkylzinc reagents to aromatic and aliphatic aldehydes. The ligands contain a tertiary amine, an aminoacid side chain, and a carbamate or amide functional group. One ligand, which was synthesized from Ile, catalyzes the addition of diethylzinc to cyclo
BOP-Cl was found to be an efficient coupling reagent for the introduction of thiopeptide bonds on imino acid residues (Pro, Sar). Boc-amino monothioacids were coupled at moderate temperature (0 degrees C-RT) with fair yields and with retained optical purity. The mechanism of the coupling reaction is discussed. Copyright (C) 1996 Elsevier Science Ltd