Benzotrithiole 2-oxides

The thermally stable bis-ozonide (1,2,4-trioxolane) of hexamethyl Dewar benzene has been isolated and its X-ray structure determined [94T7625]. Bicyclic oxadithiolane (93) has now been prepared by intramolecular reaction between dithiirane and ketone functions [94AG(E)777]. An efficient synthesis of benzotrithiole oxide (94) has been reported [93SUL5] and the stable benzotriselenole (95) has been prepared [94CC1593]. 

Irradiation of the 1,2,3-benzotrithiole 2-oxide (41) with a high-pressure mercury lamp afforded the corresponding 1-oxide (111) <93TL673>. This rearrangement, which was also observed for a number of related benzotrithiole 2-oxides, was shown to be an intramolecular process by cross-over experiments using 0-labeled materials. 

Benzotrithiole 2-oxide (41) was obtained in 76% yield from the reaction of benzene-1,2-dithiol with thionyl chloride <93TL673>. Similarly, 1,3,2-benzodioxathiole 2-oxide was prepared from 1,2-dihydroxybenzene and thionyl chloride <66HC(2i-i)i>, and 1,2,3-benzoxadithiole 2-oxide was obtained from 2-mercaptophenol and thionyl chloride <81AG(E)570>. Reaction of the monosodium salt of 1,2-dihydroxybenzene with sulfuryl chloride afforded an intermediate chlorosulfate ester, which was dehydrochlorinated to 1,3,2-benzodioxathiole 2,2-dioxide by the action of pyridine <66HC(21-l)l>. The substituted 1,3,2-benzodioxathiole 2,2-dioxide (121) was isolated from the photolysis of pyrenedione in the presence of sulfur dioxide <87TL2057>. 

No significant developments have been reported since the publication of <1996CHEC-II(4)545>. The photochemical rearrangement of 1,2,3-benzotrithiole S-Z-oxide into the corresponding. Y-l -oxide probably remains the only example <1993TL673, 1996CHEC-II(4)545>. 

Benzotrithiole. Y-oxide is capable of causing efficient DNA cleavage in the presence of 2-mercaptoethanol or glutathione and exhibited potent cytotoxicity against certain cancer cell lines <2002BML3259>. 

Finally, though not strictly a sulfoxide, the quantitative intramolecular oxygen migration reaction of benzotrithiole-2S-oxide 231 to 232 merits report [116,117]. This reaction is irreversible and not observed thermally. The reaction was proved not to be intermolecular by double label experiments and the... 

---