4,14-Dioxa-3,15-disilaheptadec-6-ene,9,10-dimethoxy-5-[(1S)-1-methoxy-2-propen-1-yl]-2,2,3,3,6,8,12,16,16-nonamethyl-15,15-diphenyl-, (5S,6E,8S,9R,10S,12S)-