Dihydromikanolide

(1aS,1bR,2aR,6R,6aR,7R,9aS,10aS)-1a,1b,2a,6,6a,7,8,9a,10,10a-Decahydro-7,10a-dimethyl-4H-6,3-methenofuro[3,2-c]bisoxireno[f,h]oxacycloundecin-4,8-dione