(11bR)-4-Hydroxy-2,6-bis(4-methoxyphenyl)-8,9,10,11,12,13,14,15-octahydrodinaphtho[2,1-d:1',2'-f][1,3,2]dioxaphosphepine 4-oxide

(11bR)-4-Hydroxy-2,6-bis(4-methoxyphenyl)-8,9,10,11,12,13,14,15-octahydrodinaphtho[2,1-d:1',2'-f][1,3,2]dioxaphosphepine 4-oxide,