(11aS)-3,7-Bis[3,5-bis(tert-butyl)-4-methoxyphenyl]-10,11,12,13-tetrahydro-10,10,13,13-tetramethyl-5-hydroxy-5-oxide-diindeno[7,1-de:1',7'-fg][1,3,2]dioxaphosphocin, 98%, (99% ee)