(5R,6R,7R,8S)-5,6:7,8-di-O-methylethylidene-dodeca-3(E),9(E),11-triene-2-one-5,6,7,8-tetraol 、
(5R,6R,7R,8S)-5,6:7,8-di-O-methylethylidene-dodeca-3(E),9(Z),11-triene-2-one-5,6,7,8-tetraol 生成 1-[(2S,6R,7R,11R,12R,13R)-4,4,9,9-tetramethyl-3,5,8,10-tetraoxatetracyclo[10.4.0.02,6.07,11]hexadeca-1(16),15-dien-13-yl]ethanone