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

rac-3-acetyl-1,1-ethylenedioxy-1,2,3,4-tetrahydro-3-hydroxy-5,8-dimethoxynaphthalene

3-acetoxy-3-acetyl-1,1-ethylenedioxy-1,2,3,4,5,8-hexahydro-5,8-dioxonaphthalene

3'-acetoxy-3'-acetyl-1',2',3',4',5',8'-hexahydro-5',8'-dioxospiro<1,3-dithiolan-2,1'-naphthalene>

methyl 3'-acetoxy-1',2',3',4',5',8'-hexahydro-5',8'-dioxospiro<1,3-dithiolan-2,1'-naphthalene>-3'-carboxylate