(11bR)-4-Hydroxy-2,6-bis(4-nitrophenyl)dinaphtho[2,1-d:1',2'-f][1,3,2]dioxaphosphepine 4-oxide

(11bR)-4-Hydroxy-2,6-bis(4-nitrophenyl)dinaphtho[2,1-d:1',2'-f][1,3,2]dioxaphosphepine 4-oxide