Reductive ring opening of 3,5-bis(2-arylethenyl)isoxazoles with molybdenum hexacarbonyl: A novel route to symmetrical and unsymmetrical curcumin derivatives

Curcumin derivatives were successfully synthesized from 3,5-dimethylisoxazole by lateral metalation and condensation with various aromatic aldehydes sequentially at C5- and C3-methyl groups. After dehydration, further transformation of isoxazole ring to b-diketone moiety was accomplished by reductive ring opening using molybdenum hexacarbonyl [Mo(CO)6] and subsequent simple acidic hydrolysis.