Synthesis and Biological Evaluation of 7-Deoxy Analogues of the Human Rhinovirus 3C Protease Inhibitor Thysanone



The synthesis of (±)-7-deoxythysanone and three analogues has been developed. The key oxa-Pictet–Spengler reaction enabled the synthesis of the naphthopyran precursor, which could be readily converted to 7-deoxythysanone and three related analogues. The biological activity of these compounds was also evaluated against HRV 3C protease, the results of which suggest that inhibition of the enzyme requires the presence of the 7-oxa functionality.