One-Pot synthesis of photochromic naphthopyrans in the solid state
p-TsOH-catalyzed condensation reactions of 1,1-diaryl-2-propyn-1-ol (1) and 2-naphthol (2) in the solid state gave 3, 3-diaryl-3H-naphtho[2,1-b]pyran (6) via Claisen rearrangement. Similar reactions of 1 with 2,6- (7) and 2,7-dihydroxynaphthalenes (8) afforded naphthodipyrane derivatives 9 and 10, respectively. Bis-naphthopyran derivatives 12 were also obtained by the reaction of 1,1,6,6-tetraaryl-2,5-hexadiyn-1,6-diol (11) and 2-naphthol (2) in the solid state.
Tanaka
K
Department of Applied Chemistry, Faculty of Engineering, Ehime University, Matsuyama, Ehime 790-8577, Japan, and Department of Chemistry, Faculty of Science and Technology, Keio University, Hiyoshi 3, Kohoku-ku, Yokohama 223-8522, Japan.
Aoki
H
Hosomi
H
Ohba
S