FIELD: biochemistry. SUBSTANCE: described is method of preparing cyclosporin of formula II: wherein A is residue of 3'-dexoxy-3'-oxo-HeBmt: B is alpha Abu-, Thr-, -Val- or Nva; X is Sar- or residue of optically active alpha-N- methylated alpha-amino acid in D-configuration: and Y is Val- or when B is Nva. Said method comprises selective oxidation of intermediate cyclosporin of formula II wherein A is MeBmt, dimethyl sulfoxide in combination with N,N'-dicyclohexyl carbodiimide or dodecylmethyl sulfoxide in combination with N,N'-dicyclohexyl carbodiimide. EFFECT: simplified process, more ecological process and increased yield of the desired product. 9 cl, 1 ex
Authors
Dates
2001-07-20—Published
1996-08-16—Filed