1',2',3',4'-tetrahydro-2'-hydroxy-5',8'-dimethoxyspiro[1,3-dithiolane-2,4'-naphthalene]-2'-carboxylic acid

methyl 1,1-ethylenedioxy-1,2,3,4-tetrahydro-5,8-dimethoxynaphthalene-3-carboxylate

(-)-1',2',3',4'-tetrahydro-3'-hydroxy-5',8'-dimethoxyspiro<1,3-dithiolan-2,1'-naphthalene>-3'-carboxylic acid

1,2,3,4-tetrahydro-5,8-dimethoxy-4-oxo-2-acetyl-2-hydroxynaphthalene cyclic 4-(ethylene mercaptole)