The synthesis of a 3‐arylisoquinoline alkaloid, decumbenine B, was accomplished in a reaction sequence based on the formation of an indolizine ring {dibenz[a,f]indolizin‐5(7H)‐one} followed by its cleavage at the amide bond, starting with an interaction of 5,6‐(methylenedioxy)isoquinoline with 2‐bromo‐5,6‐(methylenedioxy)benzoyl chloride in the presence of Bu3SnH.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)

Phosphane-free Pd 0 -catalyzed intramolecular aromatic amination was studied. o-Halophenethylamines and 3-(o-halophenyl)propylamines were found to be transformed into indolines and quinolines in a catalytic system based on Pd(OAc) 2 and Cu(OAc) 2 in the presence of K 2 CO 3 . Application of the method to substrates containing isoquinoline rings -the 1-(o-bromobenzyl)-3,4-dihydroisoquinolines 6, the 1-(o-bromobenzyl)-1,2,3,4-tetrahydroisoquinolines 7, and the 1-(o-bromophenethyl)isoquinolines 9 -provided the indolo[2,1-a]isoquinoline and dibenzo[a,f]quinolizine ring

Five new 3-O-alkyl-4a,10a-dihydrofusarubins (2-6) were isolated from the culture filtrate of a strain of Fusarium sp. (Mj-2), together with the known metabolite, anhydrofusarubin (1). The structures of the new metabolites were elucidated by spectroscopic analyses to be 3-O-butyl, 3-O-3'-methylbutyl, 3-O-2'-methylbutyl and 3-O-2'-phenylethyl-4a,10a-dihydrofusarubin A, and an isomer of 3-O-2'-phenylethyl-4a,10a-dihydrofusarubin A. Their antifungal and antibacterial activities were evaluated together with a 3-O-methyl derivative (7) prepared from 3-O-butyl-4a,10a-dihydrofusarubin A (2), indicating that the size of the O-substituent at C-3 in the 4a,10a-dihydrofusarubins negatively affected the metabolites' antimicrobial activity.

Alkaloids U 0600 Synthesis of a 3-Arylisoquinoline Alkaloid, Decumbenine B. -(WADA, Y.; NISHIDA, N.; KURONO, N.; OHKUMA, T.; ORITO*, K.; Eur. J. Org.

Various indoles and pyridine‐fused four‐ and pentacycles are prepared by the title methods, involving alkaloid precursors such as (XVI).