11-(tert-butyl-dimethyl-silanyloxy)-7-[1-(tert-butyl-dimethyl-silanyloxy)-3-(4-methyl-3,6-dihydro-2H-pyran-2-yl)-allyl]-18-methoxy-13-methylene-6,21-dioxa-bicyclo[15.3.1]henicosa-3,9,19-trien-5-one 生成 ER-809547 、 (3Z,9E)-(1R,7S,11R,17R,18S)-11-(tert-Butyl-dimethyl-silanyloxy)-7-[(E)-(S)-1-(tert-butyl-dimethyl-silanyloxy)-3-((S)-4-methyl-3,6-dihydro-2H-pyran-2-yl)-allyl]-18-methoxy-13-methylene-6,21-dioxa-bicyclo[15.3.1]henicosa-3,9,19-trien-5-one