7,8-Dioxo-A-norerythrinan (A) was synthesized from acid catalyzed cyclization of 6a-hydroxv-1-(2-phenylethyl)-octahydrocyclo-penta[b] pyrrole-3a-carboxylic acid ethyl ester (B) with concomitant deethoxycarbonylation. The intermediate (B) was a hydroxylated compound of N-acyliminium (C). The unstable pyrrolinium (C) was prepared from oxalylation of the enamine of phenethylamine and ethyl 2-oxocyclopentanecarboxylate.