2-Phenylthio-3-bromopropene, a valuable synthon, easily prepared by a simple rearrangement.
[reaction: see text] Treatment of allyl phenyl sulfide with bromine, followed by aqueous sodium hydroxide, provides a good yield of 2-phenylthio-3-bromopropene 2 via a mechanism that is elucidated by isolation of the 1,3-dibromo-2-(phenylthio)propene intermediate 7. Three uses of 2 as an annulating agent for cycloheptanone are illustrated, demonstrating that this reagent is a synthetic equivalent of acetonyl halide and an alpha-halo vinyllithium. It is also readily converted to the useful synthons 2,3-bis(phenylthio)propene 16 and 2-phenylthio-3-(phenylsulfonyl)propene 17.
Chen
Wenbo
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Key Laboratory of Organofluorine Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, PR China.
Zhao
Xiaoming
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Lu
Long
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Cohen
Theodore
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