Total synthesis of erythrinan alkaloids was achieved by a strategy based on the Diels-Alder reaction of activated butadienes to a dioxopyrroline. The reaction of isoquinolinopyrrolinedione (15) with 1, 3-bis-O-substituted butadienes proceeded in a regiospecific and stereoselective manner to give erythrinan derivatives (20) and (21). Lithium borohydride reduction of the adduct (20) or (21), followed by acid hydrolysis afforded the enone (33). Mesylation of 33 and subsequent demethoxycarbonylation of 42 under neutral conditions gave the dienone (43). Meerwein-Ponndorf reduction of 43 and subsequent methylation afforded erysotramidine (2a) and 8-oxoerythraline (2b). Aluminum hydride reduction of the 8-oxo derivatives (2) furnished dl-erysotrine (1a) and dl-erythraline (1b).