Thiosuccinic anhydride

Thiols and phosphines add to maleic anhydride to give a-thiosuccinic anhydrides (82) and phosphoranylidene—maleic anhydride adducts (83). Triethyl phosphite [122-52-1] reacts with maleic anhydride to give the yhde stmcture (23) (84). Hydrolysis of this adduct (23) leads to succinic acid... 

Reactions with Sulfur Compounds. Thiosuccinic anhydride [3194-60-3] is obtained by reaction of diethyl or diphenyl succinate [621-14-7] with potassium hydrogen sulfide followed by acidification (eq. 10). Thiosuccinic anhydride is also obtained from succinic anhydride and hydrogen sulfide under pressure (121). 

Potential 2,5-dihydroxy compounds (185) exist in the dicarbonyl forms (186). Succinic anhydride (186 Z = O) on silylation is converted into 2,5-bis(trimethylsilyloxy)furan (187) the latter compound readily participates in Diels-Alder addition reactions (80TL3423). Reaction of thiosuccinic anhydride (186 Z = S) with the triphenylphosphorane Et02CH=PPh3 gives a product which exists in the aromatic form (188) (75LA1967). 

Thiosalicylic acid, 22 25 Thiosemicarbazides, 13 575 Thiosquarylium dyes, 20 518 Thiosuccinic anhydride, 23 422 Thiosulfate, as a color film fixing agent, 19 261... 

Electrophilic attack by aldehydes can also take place at positions 3 and 4 in suitably substituted thiophenes. Thus, 2,5-bis(trimethylsilyloxy)thiophene reacts with aromatic aldehydes in the presence of the Lewis acid trimethylsilyl trifluoromethanesulfonate (0.1-1.0%) to form 3,4-disubstituted thiosuccinic anhydrides (88) in quantitative yield. With aliphatic aldehydes, the yields are lower, the catalyst being ZnBry, the products so obtained have been hydrolyzed in the presence of lead acetate to form the lactones (89) in 30-40% yields. 2,5-Bis(trimethylsilyloxy)thiophene also reacts with orthoesters in the presence of trimethylsilyl triflate to form (90) <87C152,92LA615>. 

Ng PY, Masse CE, Shaw JT. Cycloaddition reactions of imines with 3-thiosuccinic anhydrides synthesis of the tricyclic core of martinellic acid. Org. Lett. 2006 8 3999-4002. 

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