Synthesis of Enniatin-like Cyclic Depsipeptidesvia ‘Direct Amide Cyclization’
作者:Peter Köttgen、Anthony Linden、Heinz Heimgartner
DOI:10.1002/hlca.200690069
日期:2006.4
The synthesis of several 18-membered cyclodepsipeptides with an alternating sequence of α,α-disubstituted α-amino acids and α-hydroxy acids (compounds 14a–14e) is described. The ring closure via macrolactonization was accomplished by treatment of a diluted suspension of the corresponding linear precursors 12a–12e in toluene with HCl gas, i.e., the so-called ‘direct amide cyclization’. The incorporation