Alchornea javanensis

Alchornine (73) and alchornidine (74a or 74b) have been isolated by Hart et al. (126) from the bark and leaves of Alchornea javanensis (Bl.) Muell.-Arg. (Euphorbiaceae), a small tree of the New Guinea rain forest. From spectroscopic data and chemical evidence, the major alkaloid alchornine was shown to have the hexahydroimidazo[l,2-a]pyrimidine structure 73. Hydrolysis of a minor alkaloid, alchornidine, with ethanolic potassium hydroxide gave alchornine and 2,2-dimethylacrylic acid. But alchornidine is not simply an A-acyl derivative of alchornine, because mild hydrolysis with dilute acetic acid gives an isomer of 73. This isoalchornine can be shown to be 75, and it is readily converted to alchornine by reaction with alkali. This... 

Pterogynidine (picrate, mp 105°) was isolated from this plant in addition to the pteroginine (187) which had previously been reported and which is identical with a base isolated from Alchornea javanensis (p. 509) (216a, 217). 

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