title: Convergent Synthesis of Naphthylisoquinoline Alkaloids: Total Synthesis of (+)-O-Methylancistrocline.
abstract: A highly convergent synthesis of the methyl ether derivative 2a of the naphthylisoquinoline alkaloid ancistrocline (2) is described. The key step involves a stereoselective biaryl coupling between the chiral oxazoline 3 and the Grignard reagent 4 derived from the optically active tetrahydroisoquinoline 8. The atropisomeric mixture was then converted to the separable acetamides 11 and 12, which were obtained in a ratio of 16:84 and an overall yield of 32% for the three steps. The major atropisomer 12 was then converted into O-methylancistrocline (2a), which was identical to a semisynthetic sample derived from the related alkaloid ancistrocladinine (14).
authors.affiliation: Institut für Organische Chemie der Universität, Am Hubland, D-97074 Würzburg, Federal Republic of Germany.
authors.forename: Phung
authors.initials: P
authors.lastname: Chau
authors.forename: Ivona R.
authors.initials: IR
authors.lastname: Czuba
authors.forename: Mark A.
authors.initials: MA
authors.lastname: Rizzacasa
authors.forename: Gerhard
authors.initials: G
authors.lastname: Bringmann
authors.forename: Klaus-Peter
authors.initials: KP
authors.lastname: Gulden
authors.forename: Manuela
authors.initials: M
authors.lastname: Schäffer