Cassytha alkaloids. III. Aporphine alkaloids from Cassytha melantha R. Br

Abstract

The major alkaloid of Cassytha melantha R.Br, and Cassytha glabella R.Br. is (+)-9-hydroxy-10-methoxy-1,2-methylenedioxyaporphine (cassythicine), which has not been previously found to occur naturally, although the (±)-form has been synthesized by Tomita and Kikkawa. A minor alkaloid from C. melantha, isolated only in the form of an NO- diacetyl derivative, appears to be the noraporphine corresponding to cassythicine and it is presumably identical with the known alkaloid actinodaphnine. A study has been made of the N.M.R. spectra of a number of N- acetyl-N-methylaminoethylphenanthrenes, obtained from aporphines by heating with acetic anhydride. These show not only the expected splitting of the N-methyl and N-acetyl signals due to cis-trans isomerism of the amide group, but also a long-range splitting of the signals from certain aryl protons.