C=C(C)[C@@H]1CC[C@]2(C)O[C@](C)(/C=C/C[C@]3(C)O[C@H]3C1)CC[C@@H]2O (1S,2E,5S,7S,9R,12S,13S)-1,5,12-trimethyl-9-(prop-1-en-2-yl)-6,16-dioxatricyclo[10.3.1.0^{5,7}]hexadec-2-en-13-ol