Flavans: Synthetic Strategies: A Review

Flavans consist of the 2-phenylchroman structural unit found naturally in the plant kingdom. They are important compounds due to their various pharmacological properties, such as anticarcinogenic, anti-inflammatory, antioxidant, antimalarial, antiviral properties and chemopreventive potential for Helicobacter pylori peptic ulcers. Because the flavans are only minutely available from natural sources improved synthesis of flavans are desirable to obtain sufficient quantities for biological testing. Thus, this review article aims at describing the synthetic protocols which exist in the literature. From the surveyed literature 153 synthetic flavans, flavens, isoflavan, neoflavans and anthocyanins were reported.