Phenylsulfanyl migration

Holla, E. W. Napierski, B. Rebenstock, H.-P. Short and efficient synthesis of (2S)-3-(l, l -dimethylethylsulfonyl)-2-(l-naphthylmethyl)-propionic acid, N-terminal building block for protease inhibitors. Synlett 1994, 333-334. Eames, J. Fox, D. J. de las Heras, M. A. Warren, S. Stereochemically controlled synthesis of l,8-dioxaspiro[4.5]decanes and l-oxa-8-thi-aspiro[4.5]decanes by phenylsulfanyl migration. J. Chem. Soc. Perkin Trans. 1 2000,1903— 1914. 

Acylated or mesylated aldehyde adducts 301 react with enol silyl ethers 302 to provide products 303, after a phenylsulfanyl migration reaction. Oxidation of compounds 303 with MCPBA followed by heating under mesitylene reflux and acidic hydrolysis afforded 1,3-diketones 304, whereas treatment with potassium fert-butoxide followed by acidic hydrolysis provided 1,4-diketones 305 (Scheme 79)478. 

The reaction of bis(phenylsulfanyl)alkyllithiums with trialkylboranes provides the adduct 144, after elimination of phenylsulfanyllithium. Final oxidation with hydrogen peroxide-dioxane in aqueous sodium acetate afforded aldehydes or ketones in good yields (Scheme 40)151,152. However, this process cannot be carried out with 2-lithio-l,3-dithiane because the initially formed borate did not undergo the spontaneous alkyl migration reaction152. 

Migration of the phenylsulfanyl group was suggested as a key step in formation of 2,5-disubstituted furans 243 and 244 from ketopropargyl sulfides 245, by heating them at 130 °C in the presence of catalytic amounts of Cul... 

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