Synthesis and Transformation of Halochromones

Natural and synthetic chromone derivatives have been assigned as lead structures in drug development with some already being marketed [3]. The majority of the naturally occurring chromones are 2and 3-aryl derivatives, called flavones 1b and isoflavones 1c, respectively. However, other types of chromones have also been found in the plant kingdom, such as 3-methylchromones 1d and 2styrylchromones 1e (Fig. 1).