(2R,3S,4aR,5aS,7R,7aR,8aS,9aR,11S,12R,13aS,14aR,16aS,17aR,18aS)-12-(benzyloxy)-11-(2-(benzyloxy)ethyl)-7,11,13a,14a,18a-pentamethyl-2-vinyldocosahydropyrano[2'',3'':5',6']pyrano[2',3':6,7]oxepino[3,2-b]pyrano[2',3':5,6]pyrano[2,3-f]oxepin-3-ol