Photochromic 2h-chromenes annelated at c5-c6 and their methods of preparation

摘要

Described herein are C 5 -C 6 annelated naphthopyrans that possess at least one electron-withdrawing group. The compounds possess desirable properties such as increased fading kinetics. Also described herein are new methods for synthesizing 2H-chromenes annelated at C 5 -C 6 . The methods involve less stringent reaction conditions as well as provide increased reaction yields. The methods permit the synthesis of a wide variety of substituted naphthopyrans that can be temperature sensitive, which was not possible with previous synthetic routes.