Synthese und Reaktionen von Droso‐ und Isodrosopterin. Pteridine, LIV

Abstract
The synthesis of the Drosophila pigments droso‐ and isodrosopterin (7) from 7.8‐dihydropterin (3) and 2‐hydroxy‐3‐oxobutyric acid (4) is described. A reaction mechanism is discussed and proven by isotope experiments. Droso‐ and isodrosopterin form in weak acidic medium in the presence of NH ions two red reaction products each one of which seems to be identical with neodrosopterin.