(11aR)-12-Hydroxy-1,10-bis(triphenylsilyl)-4,5,6,7-tetrahydrodiindeno[7,1-de:1',7'-fg][1,3,2]dioxaphosphocine 12-oxide

(11aR)-12-Hydroxy-1,10-bis(triphenylsilyl)-4,5,6,7-tetrahydrodiindeno[7,1-de:1',7'-fg][1,3,2]dioxaphosphocine 12-oxide,