A rearrangement product of cinchonine or cinchonidine obtained by boiling with acetic acid: Pasteur, Compt. Rend. 37, 110 (1853). Miller, Rohde, Ber. 33, 3214 (1900). Conversion to cinchonidinone and cinchonine: Rabe, Ber. 44, 2088 (1911); 41, 62 (1908). Prepn from cinchonine: Prostenik, Prelog, Helv. Chim. Acta 26, 1965 (1943).