Synthesis 2019; 51(02): 433-440
DOI: 10.1055/s-0037-1610276
paper
© Georg Thieme Verlag Stuttgart · New York

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

Iván Cortés
a   Instituto de Química Rosario (IQUIR, CONICET-UNR) and Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Suipacha 531, 2000 Rosario, Argentina   Email: kaufman@iquir-conicet.gov.ar   Email: bracca@iquir-conicet.gov.ar
,
Carla M. Borini Etichetti
b   Instituto de Biología Molecular y Celular de Rosario (IBR, CONICET-UNR) and Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Esmeralda y Ocampo, 2000 Rosario, Argentina
,
Javier E. Girardini
b   Instituto de Biología Molecular y Celular de Rosario (IBR, CONICET-UNR) and Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Esmeralda y Ocampo, 2000 Rosario, Argentina
,
a   Instituto de Química Rosario (IQUIR, CONICET-UNR) and Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Suipacha 531, 2000 Rosario, Argentina   Email: kaufman@iquir-conicet.gov.ar   Email: bracca@iquir-conicet.gov.ar
,
Andrea B. J. Bracca*
a   Instituto de Química Rosario (IQUIR, CONICET-UNR) and Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Suipacha 531, 2000 Rosario, Argentina   Email: kaufman@iquir-conicet.gov.ar   Email: bracca@iquir-conicet.gov.ar
› Author Affiliations
Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET, PUE IQUIR 2016), Agencia Nacional de Promoción Científica y Tecnológica (ANPCyT, PICT 2014-0445), and Instituto Nacional del Cáncer (INC, Asistencia Financiera a Proyectos de Investigación III, 2015).
Further Information

Publication History

Received: 28 July 2018

Accepted after revision: 22 August 2018

Publication Date:
20 September 2018 (online)


Abstract

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.

Supporting Information