Über Pterinchemie 67. Mitteilung Zum Verlauf der katalytischen Reduktion von 6, 7-Diphenylpterin

On the pathway of the catalytic reduction of 6,7-diphenylpterin The pathway of the hydrogen addition to the pyrazine ring of 6, 7-diphenylpterin ( 1a ) during acid-catalyzed reduction was elucidated. Initial hydrogenation of the 5, 6-double bond produces 6, 7-diphenyl-5, 6-dihydropterin ( 2a ); this then undergoes a [1, 2]-H-rearrangement, which yields the thermodynamically more stable 6, 7-diphenyl-7, 8-dihydropterin ( 3a ). Subsequent reduction of 3a gives 4 .