methyl (S)-1',2',3',4-tetrahydro-2'-hydroxy-5',8'-dimethoxyspiro[1,3-dithiolane-2,4'-naphthalene]-2'-carboxylate

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

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