Heterolytic fragmentation of 1,3-dithianyl tosylates

✍ Scribed by James A. Marshall; John L. Belletire

• Book ID: 104247505
• Publisher: Elsevier Science
• Year: 1971
• Tongue: French
• Weight: 191 KB
• Volume: 12
• Category: Article
• ISSN: 0040-4039
• DOI: 10.1016/s0040-4039(01)96577-3

✦ Synopsis

The class of organic reactions known as heterolytic fragmentations' has figured prominently in multistep synthesis over the past several years.

3 We report herein a new member of this class in which, at least formally, a 1, 3-dithiane anion4 serves as part of the electrofugal group' in the fragmentation reaction. Although our work has thus far dealt only with cyclohexyl systems, we expect this reaction to apply to a variety of cyclic and acyclic systems according to the following expression: In the case of cyclic systems (e. g. 7 --B)the substituted ketene thioacetal products can be made to undergo a number of synthetically useful transformations, 5 thus enhancing the value of the above fragmentation scheme. The known y-lactone &' upon basic methanolysis followed by treatment with p-toluenesulfonyl chloride in pyridine afforded the diester & [m. p. 85-860, AFg 5.80, 7.41, 8.42, CDCl 8.53 and 10. '70pm; dTMs 3 7.53 (aromatic AB, J = 9 Hz, dVAB = 28 Hz), 3.84 (OCH,), and 2.44 p. p. m. (CH,)]. Reduction with lithium aluminum hydride in tetrahydrofuran at -30° and subsequent oxidation with Collins' reagent' yielded the aldehyde & [8% yield based on diester No.13