Total Synthesis and Cytotoxic Activity of 6,8-Dimethoxy-1,3-dimethylisoquinoline Isolated from Ancistrocladus tectorius: A 6π-Azaelectrocyclization Approach

CORTéS, IVáN; BORINI ETICHETTI, CARLA M.; GIRARDINI, JAVIER E.; KAUFMAN, TEODORO S.; BRACCA, ANDREA B. J.

SYNTHESIS-STUTTGART

GEORG THIEME VERLAG KG

Año: 2019 vol. 51 p. 433 - 440

0039-7881

A facile and convenient approach toward the total synthesis of 1,3-dimethyl-6,8-dimethoxyisoquinoline from phloroacetophenone is reported. The sequence entailed the selective 2,4-di-O-methylation and further triflation of the resulting phenolic product. This was followed by a Stille-type allylation, an allyl-to-propenyl isomerization, and the methoximation of the carbonyl moiety. A final microwave-assisted 6ð-azaelectrocyclization completed the sequence. Functionalized derivatives on C-1 were also prepared. The heterocycles exhibited cytotoxic activity.