Chemistry 1.2- Dithietes

Tlie present chapter reviews the chemistry of three- and four-membered ring compounds containing an S—S bond in their ring. Dithiiranes 1,2-dithietanes and 1,2-dithietes are the compounds of this type. Although 1,3-dithietanes are four-membered heterocycles which are prepared much more easily and are seemingly more familiar, they have no S-S bond in the ring and hence are not included in this chapter. 

Progress in the chemistry of three- and four-membered rings containing two sulfur atoms has been rapid in the past few years. An updated survey of the chemistry of dithiiranes, 1,2-dithietanes, and 1,2-dithietes is now provided from a major center in this area by Professor J. Nakayama and Dr. A. Ishii (Saitama University, Japan). 

The a-dithionc 91, generated by photolysis of 92, is transformed into the dithiin 93 (41%) in the absence of a trapping agent. The conversion was proposed to proceed by a [4 + 2] cycloaddition of 91 with its dithiete tautomer 94 leading to the dithietane 95, which was followed by loss of S2 (85JOC1550). Such [4 + 2] dimerizations are often encountered in the chemistry of 1,2-dithietes as discussed later. 

Juzo Nakayama is a professor of the department of chemistry at Saitama University and the vice president for research work of the same University. He received an award from the Society of Synthetic Organic Chemistry, Japan and the International Council on Main Group Chemistry for Excellence in Main Group Chemistry (ICMGC Award). His research interests include the chemistry of a range of sulfur-containing heterocycles (dithiiranes, thiirenes, dithietes, thiophenes, etc.), and sulfur-containing inner salts. 

The synthesis of dithiins may proceed via 1,2-dithiete intermediates. In these cases, yields of dithiins are usually low but the chemistry is interesting <93BCJ623>. 

A review, which includes the chemistry of 1,2-dithietes and 1,2-dithietanes, is available <00AHC221>. The dithiete 37 is one of three products obtained after chromatography when diadamantylacetylene reacts with S CU <00TL8349>. 

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