Study On4-Hydroxy-6-methyl-2-pyrone-involved Multicomponent Reactions Under Microwave Heating

This thesis consists of four parts.The first part shows the application of microwave technology and multicomponent reactions in the synthesis of heterocyclic compounds home and abroad, the base of the selection of the subject and research methods.In the second part, the multicomponent construction of indole compounds under microwave irradiation has been developed. A series of potentially biological active poly substituted indoles were synthesized in HOAc through microwave-assisted three-component reaction of arylglyoxal monohydrate, enaminones, and4-hydroxy-6-methyl-2-pyrone. The reaction has the advantages of simple one-pot operation, inexpensive starting materials and short reaction time.In the third part, the synthesis of quinoline-2,5-dione derivatives with diastereoselectivity and high yields has been established through three-component reaction of enaminones, arylaldehydes and4-hydroxy-6-methyl-2H-pyran-2-one in aqueous media with acetic acid as catalysts under microwave irradiation. Many compounds with quinoline rings have highly physiological activity as well as pharmacological activity, so efficient synthesis of quinoline derivatives has become one of the problems to be solved in organic synthesis for chemical workers.The four part involve novel multicomponent annulations of enaminones with o-phthalaldehyde (OPA) and4-hydroxy-6-methyl-2H-pyran-2-one divergently yielding multifunctionalized pyrano [3’,2’:2,3]indeno [2,1-c]quinolines and [3,4] furanoimino benzo[e]pyrano[4,3-b]oxepines. The great aspects of these domino reactions are shown by the fact that up to five new bonds and three new rings (tricyclic5-6-6skeleton including cyclopentene, pyridine, and pyrane) were readily formed in domino fasions that involved [4+1]/[3+2+1]/[5+1] cyclizations; three stereocenters including a quaternary center and geometry were controlled well in a one-pot operation. The latter provided new bicyclic7-7skeleton including azepine and oxepine via double [4+3] cyclolizations with high stereoselectivity. The present work represents the first example for constructing these special types of oxa-azaspiro and oxa-azabridged skeletons with multiple stereocenters.