1',2'-ジデヒドロ-6',7',10,11-テトラメトキシエメタン

説明Pyman first obtained this alkaloid from the non-phenolic fraction of the total alkaloids remaining after the removal of Emetine (q.v.) as the hydrobromide. So far, it has only been found in Cephaelis Ipecacuanha (Brot) A. Rich. The alkaloid may be separated from the accompanying emetamine by virtue of the fact that it is removed first by dilute HCl or H2S04 from a mixture of the two bases in CHC13. It crystallizes from hot Et20 as colourless prisms and has [c:do + 43.2° (EtOH). The salts and derivatives crystallize well, e.g. the hydro bromide tetrahydrate, pale yellow needles, m.p. 190-200°C (dry); [α]D + 48.0° (H20); the sulphate which may be obtained as the monohydrate from EtOH or the heptahydrate from H20, m.p. 247°C (dry, dec.); [α]D + 54.1° (H20); hydrogen oxalate, m.p. 150-162°C (dec.); [α]D + 45.9° (H20) and the picrate, octagonal plates from Me2CO which melts over a wide range from 142-175°C. The alkaloid gives a green colour with Frohde's reagent and dilute aqueous solutions of its salts are fluorescent.