(1R,3S,7R,8E,11S,15S,17R,21R,23S)-21-hydroxy-11-methoxy-10,10-dimethyl-5,25-dimethylidene-17-[(1R)-1-(phenylmethoxymethoxy)ethyl]-18,27,28,29-tetraoxatetracyclo[21.3.1.13,7.111,15]nonacos-8-ene-12,19-dione 在
lithium tetrafluoroborate 作用下,
以
水 、
乙腈 为溶剂,
以62%的产率得到(1R,3S,7R,8E,11S,15S,17R,21R,23S)-11,21-dihydroxy-17-[(1R)-1-hydroxyethyl]-10,10-dimethyl-5,25-dimethylidene-18,27,28,29-tetraoxatetracyclo[21.3.1.13,7.111,15]nonacos-8-ene-12,19-dione