Cycloaddition Reactions of [1,2]Dithiolo[1,2]dithiole Derivatives with Dimethyl Acetylenedicarboxylate: Formation of New Bi-, Tri- and Tetracyclic Thiopyran Derivatives

All articles of this category By cycloaddition reactions of the title compounds 1 , new spiro[1,3-dithiole-thiopyran] derivatives 3 and 5 are available. Their cleavage with mercury(II) acetate leads to the corresponding bicyclic thiopyran-4-ones 9 and 10 . Starting from 3 H ,6 H -[1,2]dithiolo[4,3- c ][1,2]dithiole- 3,6-dithione (1d) , besides 4 H ,8 H -2,3,6,7,4′,5′,4″,5″- octa-(methoxycarbonyl)thiopyrano[3,2- b ]thiopyran-4-spiro-2′-(1′,3′- dithiole)-8-spiro-2″-(1″,3″-dithiole) (5) , the tetra(5′,6′- methoxycarbonyl-1′,4′-dithiino)[2,3- c ][2,3- e ][2,3- i ] [2,3- k ]-1,2,7,8-tetrathiacyclododeca-3,5,9,11-tetraene (8) is formed.