Reaction at Sulphur Thiophen Dioxides

Reaction at Sulphur Thiophen Dioxides. - The stable S-ylide (167) was formed, in 40% yield, in the reaction of 2-isobutenylthiophen with dimethyl diazomalonate in the presence of rhodium acetate.The transient thiophen 

1- dioxide with base gave mono- and di-adducts such as (168) - (172) in the presence of 1,3-dipoles such as A -a-diphenyl nitrone and mesitonitrile oxide. The structures of the adducts were partly proven by X-ray crystallography. The reaction of C-labelled transient thiophen 1,1-dioxide with 6-dimethyl-aminofulvene has been utilized for the preparation of C-labelled azulene. Rate constants for the reaction of 2,3,4,5-tetrachlorothiophen 1,1-dioxide with para-substituted styrenes have been measured, and MO calculations on this type of cycloaddition have been carried out. The reaction of tetra-chlorothiophen 1,1-dioxide with (172) led to (173), having an iceane 

Titova, V. M. Berestovitskaya, and V. V. Perekalin, Metody Sint, Str. Khim. Prevrashch. Nitrosoedin., 1980, 37. 

5-diphenyltetrahydrothiophen 1,1-dioxide occurred with inversion to give the rrai 5-2,5-dichloro-2,5-diphenylthiophen 1,1-dioxide, as proven by X-ray crystallography. Some other aspects of the chemistry and use of dihydro-and tetrahydro-thiophen 1,1-dioxideand of sulphilimine and related derivatives have been published. 

Reaction at Sulphur Thiophen Dioxides.— Treatment of thiophenhydroximine-dicarboxylic acids (115) with Raney nickel gave 2-amino-octanedioic, 2-aminodecanedioic, and other aliphatic 2-amino-dicarboxylic acids.  

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