Ethyl ethylthiomethyl sulfoxide

Unlike the carbanions from 1,3-dithians (see Chapter 3, p. 31 and Chapter 6, p. 90), the sulfinyl carbanions have the ability to undergo Michael additions (conjugate or 1,4-additions) with a,p-unsaturated carbonyl compounds. For instance, the secondary carbanion (44) from the ethyl ethylthiomethyl sulfoxide (45) may be sucessively reacted with ethyl iodide and 3-butene-2-one to give heptan-2,5-dione (46) via the tertiary carbanion (47), as shown in Scheme 23. The carbanion (47) may also be condensed with propyl bromide, and hydrolysis of the product yields ethyl propyl ketone (48) (Scheme 23). 

Als Synthesebausteinc fiir die Aldehyd-Herstellung (Ubersicht s. Lit.360) haben Methyl-(methylthio-methyl)-(V)360"362, Ethyl-ethylthiomethyl-sulfoxid(VI)295,363,364 bzw. l,3-Dithian-S-oxid(VII)295,364-366 Anwendung gefunden. 

Aq.30%-H2O2 added with ice-cooling to a soln. of formaldehyde diethyl mercaptal in acetic acid, and stirred 2 hrs. at room temp. -> ethyl ethylthiomethyl sulfoxide. Y 83%. - Other oxidants did not give satisfactory results. F. e. s. K. Ogura and G. Tsudiihashi, Bull. Chem. Soc. Japan 45, 2203 (1972). 

Closely related procedures are based on z-a I kyIthiosu Ifoxidcs, with ethylthiomethyl ethyl sulfoxide being a particularly convenient example.119 120... 

Preparation of Ethylthiomethyl Ethyl Sulfoxide and Methyl Phenyl Sulfoxide... 

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