(13R,13aR)-5,8,13,13a-Tetrahydro-9,10-dimethoxy-6H-benzo[g]-1,3-benzodioxolo[5,6-a]quinolizin-13β-ol

This protoberberine alkaloid is the major constituent of Corydalis ophiocarpa Hook. It has [α] ²⁴ _D - 284° (CHC13) and yields a sparingly soluble hydrochloride; a methiodide, m.p. 271°C (dec.) and the O-acetate, m.p. l41-3°C (165-7°C). It contains two methoxyl groups and one methylenedioxy group and when boiled with HCl furnishes a yellow base which, on oxidation with iodine and subsequent reduction, is converted into (±)-Canadine (q.v.). The alkaloid is therefore 13- hydroxycanadine, a structure confirmed by its oxidation to 6:7-methylenedioxy_x0002_l-keto-1: 2: 3 :4-tetrahydroisoquinoline (noroxyhydrastinine), m.p. 183°C, with KMn04' The optically inactive form crystallizes as colourless needles from MeOH-CHC13 , m.p. 252°C and also gives an O-acetate as needles from petroleum ether, m.p. 172-4°C.

Manske., Can. J. Res., 17B, 51 (1939)
Govindachari, Rajaduvai., J. Chern. Soc., 557 (1957)
Ohta, Toni, Morozumi., Tetrahedron Lett., 859 (1963)