(11aR)-1,10-Bis(3,5-di-tert-butylphenyl)-12-hydroxy-4,5,6,7-tetrahydrodiindeno[7,1-de:1',7'-fg][1,3,2]dioxaphosphocine 12-oxide

(11aR)-1,10-Bis(3,5-di-tert-butylphenyl)-12-hydroxy-4,5,6,7-tetrahydrodiindeno[7,1-de:1',7'-fg][1,3,2]dioxaphosphocine 12-oxide,