Spiro1,3-dithiolo4,5-bfuran-2,3(2H)-furan, hexahydro-2,3a-dimethyl-

hexahydro-2'3a-dimethylspiro[1,3-dithiolo[4,5-b]furan-2,3'(2'H)-furan]

2',3-Dimethyl-3',4-dioxa-2,8-dithiabicyclo[3.3.0]octanespirocyclopentane

spiro{2,4-dithia-1-methy-8uxaBicyclo[3,3,0]ocatane-3,3-(1-oxa-2-methyl)cyclopantene}

Spiro[2,4-Dithia-1-methyl-8-oxabicyclo[3,3,0]octane-3,3'-(1'oxa-2'methyl)cyclopentane

3a,4',5,5',6,6a-Hexahydro-2',3a-dimethylspiro[1,3-dithiolo[4,5-b]furan-2,3'(2'H)-furan]