Synthesis of novel 2-Butadienylchromone derivatives

Chromones are a group of naturally occurring compounds with a benzoannelated ypyrone ring. A large number of chromone derivatives have been isolated from natural sources and a wide range of biological properties have been attribute to them, such as antifungal, anti-allergenic, antiviral, antitubulin, anti-hypertensive, anticancer and antioxidant activities.1 11 Studies with 2-styrylchromones demonstrated that the number and position of the hydroxyl groups in the A-ring and the 3', 4'-dihydroxy substitution on B-ring play an important role in their radical scavenger activity. In addition the molecular stabilization promoted by the carbonyl carbon C-4 and Ca=C~ double bond, also seem to contribute to the scavenging effect of these compounds. 121 Taking into account these considerations we establi sh a new synthetic route for the preparation of novel hydroxylated 2-butadienylchromone derivatives 5. Our methodology involves the condensation of methoxy-2-methylchromones zl31 with 3,4-dimethoxy- cinnamaldehyde 3141 leading to (E,E)-2-( 4-arylbuta-1 ,3-dien-l-yl)-4H-chromen-4-ones 4. The final step involves the cleavage of methyl group of 4 in order to obtain the desired hydroxylated derivatives 5 (Scheme). In this communication we will present the synthetic details of all described transformations as well as the structural characterisation (by ID and 2D NMR studies) of the new synthesi sed compounds.

Synthesis of novel 2-Butadienylchromone derivatives Conference Paper