16,19-Etheno-10,14-metheno-6H,14H,23H-pyrano[4,3-d][1,7,14]trioxacycloheneicosin-6,23-dione,4-ethylidene-3,13-bis(b-D-glucopyranosyloxy)-3,4,4a,5,8,9,20,21-octahydro-, [3S-(3R*,4E,4aR*)]-