1,3-DICARBOXYBENZANNULATION OF ACYL SYSTEMS VIA A ONE-POT MICHAEL-MICHAEL-INTRAMOLECULAR ALDOL-DEHYDRATION REACTION SEQUENCE

Reaction of the 3-lithio derivative of methyl propynoate with 4-methyl cyclohex-3-en-1-one (3) (or the lithium dienolate 6 of the enone 3 wit h methyl propynoate), contrary to the expected addition product 1, gen erated the dihydronaphthalene derivative 4, via a sequential Michael, Michael, intramolecular aldol and dehydration reactions. Oxidation wit h DDQ transformed the dihydronaphthalene 4 into the naphthalene deriva tive 5 confirming the structure of 4. Generality of this new, one-pot, three component meta-dimethoxycarbonylbenzannulation i established by the annulation of the Michael donors 10, 12-15, resulting in the arom atic products 11, 16-19.