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 6π-azaelectrocyclization completed
the sequence. Functionalized derivatives on C-1 were also prepared. The heterocycles
exhibited cytotoxic activity.
Key words
total synthesis - bioactive natural product -
Ancistrocladus tectorius alkaloid - 6π-azaelectrocyclization - cytotoxic nitrogen heterocycles
