Dimethylsulfoxonium methylide dimethyl sulfoxide

Dimethyl sulfide is a useful precursor to sulfur ylids, reacting with iodomethane to give trimethylsulfonium iodide (609). When this salt was treated with n-butyllithium, deprotonation of the hydrogen on the a-carbon led to dimethylsulfonium methylid (610). Dimethyl sulfoxide also reacts with alkyl halides to give a sulfoxonium salt. When DMSO reacted with iodomethane, trimethylsulfoxonium iodide (611) was formed. As with the dimethyl sulfide derivative, treatment with a strong base such as -butyllithium generated the corresponding ylid, dimethylsulfoxonium methylid (612). 

Dimethyl sulfoxide-d6 s.a. Potassium rert-butoxide/dimethyl sulfoxide-d6 Dimethylsulfoxonium methylid -, cyclopropanation, asym. with -44,819... 

Methylsulfinylmethane [dimethyl sulfoxide, DMSO, (013)280] reacts with methyl iodide (CH3I) to produce the trimethylsulfoxonium iodide [(013)380 I ]. The sulfoxonium iodide can be induced to eliminate hydrogen iodide (HI) by treatment with sodium hydride (NaH) in methylsulfinylmethane [dimethyl sulfoxide, DMSO, (CH3)2S0] to generate the corresponding dimethylsulfoxonium methylide [(CH3)2S (0)CH2-] (Equation 9.48). 

Scheme 9.58. A representation of the reaction of 4-(l,l-dimethylethyl)cyclohexanone (4-f-butylcyclohexanone), with dimethylsulfoxonium methylide [(CH3)2S (0)CH2 ]. Addition occurs exclusively from the equatorial direction and eUmination of dimethyl sulfoxide...

Isoderritol isoflavone in dimethyl sulfoxide added to excess dimethylsulfoxonium methylide prepared from trimethylsulfoxonium iodide and NaH in dimethyl sulfoxide, and stirred 18 hrs. at room temp. -> product. Y 68%. L. Crombie, J. S. Davies, and D. A. Whiting, Soc. (C) 1971, 304. 

A soln. of phenacyl bromide in a little tetrahydrofuran added at -30 to -20° to dimethylsulfoxonium methylid prepared from trimethylsulfoxonium iodide and NaH in dimethyl sulfoxide, and stirred at room temp, overnight -> phenyl cyclopropyl ketone. Y 37%. Also with phenacyl tosylate and f. e. s. P. Bravo et al., G. 100, 566 (1970) Tetrahedron 27, 3563 (1971). 

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