A Convenient Synthesis of Some α-Oxoketene-N,S- and N,N-Acetals

H. Loghmani-Khouzani*, M.M. Sadeghi and M.H. Ghorbani

Department of Chemistry, Isfahan University, Isfahan 81746-73441, Iran

(Received 18 July 2006, Accepted 23 September2006)

Some α-oxoketene-N,S- and N,N-acetals were selectively synthesized in good to excellent yields by the reaction of 1,1-dimethoxy-4,4-di(methylthio)-3-buten-2-one with primary and secondary amines under moderate conditions. Secondary amines in reaction with α-oxoketene dithioacetal yielded double-substitution products exclusively, whereas primary amines under the same conditions yielded the mono-substituted products as exclusive or main products.

Keywords: Nucleophilic addition-elimination, α-Oxoketene dithioacetals, α-Oxoketene-N, S-acetals, α-Oxoketene-N,N-acetals, Double-substitution