Dithiolium special

A special type of nucleophilic attack on 1,2-dithiolium compounds is the pyridine-catalyzed rearrangement of 3-[(l,2-dithiol-3-ylidene)methyl]-l,2-... 

For isomeric thienothiophenes, both general methods of synthesis and original procedures applicable only to the preparation of particular types of compounds have been developed. In recent years, along with conventional methods based on thiophene derivatives as substrates, other approaches using, in particular, cyclopropenethiones, dithiynes and dithiolium salts have been successfully designed. A special section in this review deals with high-temperature synthesis of annulated thienothiophenes and procedures used for the preparation of particular representatives of this class of heterocycles. 

An efficient conversion of cyclobutanone to a 7-lactone ring is part of a total synthesis of prostaglandins Among the various products obtained by reaction of acetylenes with carbon disulfide are those of special interest which originate by the addition of third components to intermediate 1,3-dithiolium carbenes to form 2-subst. 1,3-dithioles... 

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