Sulfoxide, ethyl ethylthio

Carbanions formed from methyl methylthiomethyl sulfoxide 94 and ethyl ethylthio-methyl sulfoxide 95 were shown to be alkylated in excellent yields126,127. Treatment of 94 with rc-BuLi or KH and subsequent reaction with 1, n-dihalo- or bis(tosyloxy)alkane gave 3-, 4-, 5- and 6-membered 1-methylsulfmyl-l-methylthiocycloalkanes128"130. Upon hydrolyses of these products, the corresponding aldehydes and ketones are obtained. 

Sulfoxid Ethyl-(1-ethyl-1-ethylthio-4-oxo-pentyl)- Ell, 798 (RS CHR-SO-R + En COOR)... 

Slight variations of the structure of this acyl anion equivalent have led in fact to the discovery of particularly valuable alternative reagents. Among them, ethyl ethylthio sulfoxide can be both monoalkyl-ated or sequentially dialkylated (Scheme 74, entries c and d). f-Butyl methylthio sulfoxide and phenyl methylthio analogs have also been monoalkylated but not dialkylated (Scheme 79, entry c Scheme 80, entry a). 

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