(11bS)-2,6-Bis(bis(3,5-di-tert-butylphenyl)methyl)dinaphtho[2,1-d:1',2'-f][1,3,2]dioxaphosphepine 4-oxide

(11bS)-2,6-Bis(bis(3,5-di-tert-butylphenyl)methyl)dinaphtho[2,1-d:1',2'-f][1,3,2]dioxaphosphepine 4-oxide