1954 年 74 巻 12 号 p. 1363-1365
Cleavage reaction of the biscoclaurine-type alkaloids, O-methyldauricine (I) and isotetrandrine (III), was carried out with the Grignard reagent, cobalt chloride as the catalyst, and tetrahydrofuran of dimethylaniline as a solvent. (I) was recovered on carrying out the reaction at a room temperature but at a boiling temperature (70-85° bath temperature in the case of dimethylaniline) for 24 hours resulted in the demethylation of the methoxyl group neighboring the oxygen bridge composing the diphenyl ether, which was not affected, and dauricine (II) was formed from (I). (II) was confirmed as its perchlorate of m.p. 215-216°. In the case of (III), the material was completely recovered in either of the solvents and it was found that this reagent is completely inactive to (III). The same treatment of 7-phenoxyquinoline (IV) in ether also ended in the recovery of the starting material.