An improved synthesis of β-keto ester units in didemnins, using 2,2'-carbonyl-bis(3,5-dioxo-4-methyl-1,2,4-oxadiazolidine)
作者:Patrick Jouin、Joël Poncet、Marie-Noelle Dufour、Isabelle Maugras、Antoine Pantaloni、Bertrand Castro
DOI:10.1016/0040-4039(88)85253-5
日期:——
N-protected α-amino acids and O-protected α-hydroxy acids with 2,2'-carbonylbis (3,5-dioxo-4-methyl-1,2,4-oxadiazolidine) 6 provide a stable activated intermediate 7 suitable for the synthesis of β-keto ester 8. This activation was used in the preparation of the non-proteogenic units 1st 1 and Hip 4 present in the cyclodepsipeptides didemnins isolated from the tunicates Didemnidae.
N保护的α-氨基酸和O保护的α-羟基酸被2,2'-羰基双(3,5-二氧代-4-甲基-1,2,4-氧二唑烷)6活化后得到稳定的中间体7适用于合成β-酮酸酯8。该活化被用于制备存在于从被膜Didemnidae分离的环二肽二聚体素中的非蛋白质形成单元1st 1和Hip 4。