(2R,4S,4aS,5aR,7aS,9R,10S,12aR,13aS,14aR)-4-(benzyloxy)-2-(3-(benzyloxy)propyl)-9-(3-((tert-butyldiphenylsilyl)oxy)propyl)-5a,10-dimethylhexadecahydrooxepino[3,2-b]pyrano[2',3':5,6]pyrano[2,3-f]oxepin-10-ol