In the course of extensive studies on the Robinson dehydrogenation reaction, 1-(3, 4-dihydroxybenzyl)-and 1-(3, 4-dihydroxyphenethyl)-1, 2, 3, 4-tetrahydro-β-carbolines (III and VI) and their N-methyl derivatives (V and VII) were oxidized. Though (III) and (V) failed in giving any definite result, (VI) and (VII) gave the same oxidation product (XI), to which was assigned the structure (II) involving additional unsaturation.
