Synthesis and cytotoxity of novel benzopyran derivatives

Chromane, chromanones and chromenones associated with interesting chemistry, form the core ring structure of a number of natural products like flavanoids, isoflavanoids, coumarins, homo-, iso- and neo-flavonoids 1,2 . Compounds representing these types of classes manifest a variety of remarkable biological activities such as anti-allergic, tyrosine kinase inhibitory, estrogen receptor agonist or antagonist or inhibitor activity of steroidegenic enzymes 3,4 . Chroman/chromanones or in simple terms benzopyrans/benzopyranones can be potential intermediates for the synthesis of heterocyclic analogs of steroids and/or important building blocks for the preparation of pterocarpans and isoflavones with strong fungicidal activity 5 . Another important activity associated with chromans having substitution e.g. at 2- and 4-positions has been that of its smooth muscle relaxant activity and these compounds have been used for the treatment of disorders such as asthma and hypertension with chromakalim 7 being the best representative example of these anti-hypertensives 6 .