(3Z,9E)-(1R,7S,11S,17R)-11-(tert-butyl-dimethyl-silanyloxy)-7-(tert-butyl-diphenyl-silanyloxymethyl)-6,21-dioxa-bicyclo[15.3.1]henicosa-3,9,19-triene-5,13-dione

(3Z,9E)-(1R,7S,11S,17R)-11-Hydroxy-7-[(E)-(S)-1-methoxy-3-((S)-4-methyl-3,6-dihydro-2H-pyran-2-yl)-allyl]-13-methylene-6,21-dioxa-bicyclo[15.3.1]henicosa-3,9,19-trien-5-one