Molecular hybridization of bioactives: Synthesis and antitubercular evaluation of novel dibenzofuran embodied homoisoflavonoids via Baylis–Hillman reaction
natural product like dibenzofuran embodied homoisoflavonoids [(E)-3-(dibenzo[b,d]furan-2-ylmethylene)chroman-4-ones] designed by molecular hybridization were synthesized in very good yields via a sequence of reactions involving base catalyzed Baylis–Hillmann (BH) reaction of 2-dibenzofuran carboxaldehyde and methyl acrylate; bromination of BH adduct; condensation of resulted allylic bromide with substituted
ldehyde (1), with different activated olefins in the presence of DABCO as the base catalyst. We observed that there is no significant effect of the solvent (methanol) on the reaction rates. In situ mass spectrometry experiments and computational studies were applied to understand the role of the reaction intermediates and their structure implications. MS data revealed that the zwitterionic intermediate