Domino Michael−Aldol Reactions on 1,4-Diarylbut-2-ene-1,4-diones with Methyl Acetoacetate Furnish Methyl 2-Aroyl-4- hydroxy-6-oxo-4-arylcyclohexane-1-carbox- ylate Derivatives†
journal contributionposted on 02.04.2004, 00:00 authored by H. Surya Prakash Rao, S. P. Senthilkumar
Domino Michael-Aldol reactions on 1,4-diaryl-2-butene-1,4-diones with methyl acetoacetate in the presence of activated Ba(OH)2 furnished methyl (1R*,2S*,4S*)-2-aroyl-4-hydroxy-6-oxo-4-arylcyclohexane-1-carboxylate derivatives in a stereo- and regiospecific manner. While treatment of these cyclohexanecarboxylate products with TsOH resulted in the dehydrated and decarbomethoxylated cyclohexenone derivatives, the reaction with NaOMe furnished 3,5-disubstituted phenols via dehydration, decarbomethoxylation, and dehydrogenation. NaCl/DMSO under microwave irradiation transformed the cyclohexanecarboxylate products to the 7-hydroxyisobenzofuranone derivatives.