与预期相反,铑类胡萝卜素不经历环加成反应,其异构体萘并吡喃3和5的2 H-吡喃单元。与3一起,形成萘并[2,1 - b ]吡喃-8-乙酸乙酸酯4,而新颖的部花菁染料6是通过萘并[1,2-]的C-5–C-6双键的环加成反应而得到的。b ] pyran 5。将类固醇束缚到萘并[1,2- b ]吡喃系统5中,如10中所示,导致添加方式相似,并提供了深色的四轮车11。
Neutral coloring photochromic 2H-naphtho[1,2-b] pyrans and heterocyclic pyrans
申请人:James Robinson Limited
公开号:US06248264B1
公开(公告)日:2001-06-19
Compositions comprising a naphtho [1,2-b]pyran of formula (I):
wherein R7 and/or R9 is hydrogen or an amino group provided that R7 and R9 are not both hydrogen, and the other substituents are as defined in the specifcation.