methyl 7'-hydroxy-2'-methoxy-6',10'-dihydro-7'H,9'H-spiro[[1,3]dioxolane-2,8'-[7,9a]methanobenzo[a]azulene]-1'-carboxylate

methyl 2'-methoxy-7'-(methoxymethoxy)-6',10'-dihydro-7'H,9'H-spiro[[1,3]dioxolane-2,8'-[7,9a]methanobenzo[a]azulene]-1'-carboxylate

(+/-)-(10α)-Dimethyl 8,8-(ethylenedioxy)-2-methoxy-7-<(methoxymethyl)oxy>gibba-1,3,4a(10a),4b-tetraene-1,10-dicarboxylate

(+/-)-(4bβ,10α)-Benzyl (8,8-ethylenedioxy)-2-methoxy-1-(methoxycarbonyl)-7-<(methoxymethyl)oxy>gibba-1,3,4a(10a)-triene-10-carboxylate