An improved synthesis of rupintrivir (AG7088) was accomplished using three amino acids (L-glutamic acid, D-4-fluorophenylalanine, and L-valine) as the building blocks. The key fragment ketomethylene dipeptide isostere was constructed with the valine derivative and phenylpropionic acid derivative, followed by coupling with a lactam derivative and an isoxazole acid chloride to provide AG7088 totally in eight steps.
LIN DaiZongQIAN WangKeHILGENFELD RolfJIANG HuaLiangCHEN KaiXianLIU Hong
A convenient and efficient method for the preparation of α-substituted β-amino acids has been developed by reacting compound 2 with various boric acid/borate 3 through Suzuki coupling reaction,which gave multiple structure types of substituted Ni（II） complexes 4 in high yields.Hydrogenation and hydrolysis of complexes 4 led to the corresponding α-substituted β-amino acids.
