Synonyms: 1,7-Dioxaspiro[5.5]undec-10-ene-2-propanoicacid, a,5-dihydroxy-8-(2-hydroxy-1-methylethyl)-a,10-dimethyl-, [2S-[2a(S*),5b,6b[R*(S*)]]]-; 1,7-Dioxaspiro[5.5]undec-10-ene-2-propanoic acid, a,5-dihydroxy-8-[(1R)-2-hydroxy-1-methylethyl]-a,10-dimethyl-, (aR,2S,5R,6R,7S)- (9CI); Okadaicacid spiroketal I