Download full text in PDF Opens in a new window. Article suggestions will be shown in a dialog on return to ScienceDirect. ... Please enable JavaScript to use all the features on this page. ... Two aromatic alkaloids, meridine (1) and cystodamine (3), and related compounds (2, 4, 5) were synthesized by hetero Diels-Alder reaction between 4-methoxy- (or 4-chloro-)5,8-quinolinedione and 2-nitrocinnamaldehyde dimethylhydrazone. ... Pentacyclic aromatic alkaloids, ...