5,6-Isopropylidenedioxyfuro[2,3-d]isoxazole-3-methanol derivative 9-((4S,5S)-4,5-Diphenylimidazolidin-2-yl)-10-aza-4,4-dimethyl-3,5,7,11-tetraoxatricyclo[6.3.0.0<2,6