Sulfides, alkyl 2-pyridyl synthesis

Scheme 23. Barton s thiohydroxamate ester chemistry synthesis of alkyl pyridyl sulfides (127).

Pinhey utilized the decarboxylative rearrangement of 2 to the nor-alkyl pyridyl sulfide 3, oxidation to the corresponding sulfoxide and thermal elimination sequence in a simple transformation of podocarpic acid 4 into useful synthons 5 (for example, in vitamin D3 synthesis) for steroid CD-ring systems, as shown in Scheme l.8... 

The reactions of disulfides, diselenides or ditellurides with O-acylthiohydroxamates provide an efficient method for the synthesis of unsymmetrical thio-, seleno-, and telluroethers respectively (Scheme 12). In this instance, low-temperature tungsten lamp photolysis is the best preparative method since competing decarboxylative rearrangement to alkyl pyridyl sulfides is problematic under thermal conditions [17]. 

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