Convenient synthesis of linear 2H,6H-pyrano[3,2-g] chromenes from natural occurring compound; visnagin

Abstract

A simple and convenient rout for the synthesis of linear 2-imino-2H,6H-pyrano[3,2-g] chromen-6-ones and 2H,6H-pyrano[3,2-g]chromene-2,6-diones has been described starting from natural occurring furochromone; visnagin (1). Ring opening of 1 yielded 6-formyl-7-hydroxy-5-methoxy-2-methylchromone (2), which underwent reaction with different acetonitrile derivatives furnished 2-imino-2H,6H-pyrano[3,2-g] chromen-6-ones (5a–h). Acid hydrolysis of 5a–h led to the formation of 2H,6H-pyrano[3,2-g]chromene-2,6-diones (6a–h). Structures of the synthesized compounds were clarified based on their elemental analyses and spectral data. The entire target compounds were selected for in vitro anticancer activity against 60 human cancer cell lines at a single dose (10⁻⁵ M) by the National Cancer Institute (NCI, Bethesda, USA).

GRAPHICAL ABSTRACT

Keywords:

• Anticancer activity
• chromone
• coumarin
• 2H,6H-pyrano[3,2-g]chromene
• visnagin

Correction Statement

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Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This work was supported by grant from the French Embassy in Egypt (Institut Français d’Egypte) and Université de Lorraine, Laboratoire Lorrain de Chimie Moléculaire (L.2.C.M.), Metz, France.