from the corresponding isoquinolinones and (2-bromophenyl)acetonitriles in four steps. This represents a convenientapproach toward the synthesis of tetracyclic alkaloids. A direct conversion of 1-(2-bromobenzoyl)isoquinolines to dibenzo[de,g]quinolin-7-ones is the key step in the total synthesis. The yield of the reductive photocyclization depends on the position of the substituents at the isoquinolyl
An improved non-oxidative photochemical synthesis of aporphine derivatives has been developed, in which o-halobenzylidenetetrahydroisoquinolines are irradiated in the presence of potassium t-butoxide. The yield (72%) of one such product, N-carbethoxynorneolitsine (25) is the highest ever reported for any cyclization producing the aporphine ring system. Compound 25 was converted in two steps to cassameridine