Cyclization of α,α′-bis(substituted-benzylidene)cyclohexanones and 4-hydroxycoumarin: synthesis of 11-benzylidene-8,9,10,11-tetrahydro-7-phenyl-6H,7H-chromeno[4,3-b]chromen-6-ones as new pyranochromene derivatives
摘要:
A series of new 11-benzylidene-8,9,10,11-tetrahydro-7-phenyl-6H,7H-chromeno[4,3-b]chromen-6-ones has been synthesized through a new Michael addition domino cyclization between alpha,alpha'-bis(substituted-benzylidene)cyclohexanones and 4-hydroxycoumarin in acetic acid at reflux conditions. Very good to excellent yields of the products, operational simplicity, and simple workup are attractive features of this synthesis protocol.