Über Pterinchemie 52. Mittelung [1] Eine eindeutige Synthese isomerenfreier Pteroyl‐γ‐L‐glutamyl‐γ‐<scp>L</scp>‐glutamyl‐<scp>L</scp>‐glutaminsäure

Abstract

Abstract A new and unequivocal synthesis of pteroyl‐γ‐L‐glutamyl‐γ‐L‐glutamyl‐L‐glutamic acid free of isomers is described. A melt of N(2′)‐acetyl‐6‐formylpterine and tetramethyl‐N‐(p‐amino‐benzoyl)‐γ‐L‐glutamyl‐γ‐L‐glutamyl‐L‐glutamatewas quantitatively converted to the corresponding azomethin IX. NaBH 4 ‐reduction followed by basic hydrolysis of acetyl and methylester groups gives pure pteroyl‐γ‐L‐glutamyl‐γ‐L‐glutamyl‐L‐glutamic acid in good yield.