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The cyclization of 3-bromo-6-methoxy-2-(naphtho[2,3-d[1,3]dioxol-5-ylaminomethyl)phenol (2) using tributyltinhydride under radical-mediated conditions was accompanied by spontaneous oxidation and afforded directly isodecarine (2-methoxy[1,3]benzodioxolo[5,6-c]phenanthridin-1-ol, (3). 2-Methoxy-6-(naphtho[2,3-d [ 1,3]dioxol-5-ylaminomethyl)-phenol (4) was isolated as a side product. Isodecarine was also prepared by the catalytic debenzylation of 7-benzyloxy-8-methoxy-2,3-methylendioxybenzo-[c]phenanthridine (5). This compound was efficiently converted to 7-benzyloxy-8-methoxy-5 -methyl-2,3-methylenedioxybenzo[c]phenanthridinium trifluoromethanesulfonate (6) in high yield and with a short reaction time.

A new bisbenzylisoquinoline alkaloid (−)-(1S,1'R)-O,O'-dimethylgrisabine was isolated from the leaves of Phaeanthus vietnamensis Ban. Its structure was determined on the basis of the extensive 2-D and 1-D nmr long-range heteronuclear correlations. Its antibacterial activity is also described