The first total synthesis of the new type of cytocydal beta-carboline alkaloid oxopropaline G was achieved in 12 steps. (C) 1998 Elsevier Science Ltd. All rights reserved.
Total Syntheses of Novel Cytocidal .BETA.-Carboline Alkaloids, Oxopropalines D and G.
was synthesized by thermal electrocyclicreaction of a 1-azahexatriene system, involving the indole 2,3-bond. The key compound N-methoxymethyl-1-methoxycarbonyl-4-methyl-beta-carboline (2) was then prepared in a four-step sequence. The total synthesis of oxopropaline G (1e) was achieved from this key compound in four steps. Furthermore, the enantioselective totalsyntheses of (+)-oxopropaline D (1c)