Abstract The course of the H OFMANN degradation in the 2-oxo-3-alkyl-9, 10-dimethoxy-1, 2, 3, 4, 6, 7-hexahydro-11bH-benzo [a] quinolizine series has been elucidated and the constitution of the degradation products established. They represent 1, 2, 3, 4- tetrahydroisoquinoline derivatives obtained by ring opening between the nitrogen atom and the carbon atom 4. In addition, a new synthesis of substituted 2-oxo-9, 10-dimethoxy-1, 2, ...
