[72298-22-7] · C11H15NO2S · (R)-(+)-a-(p-Tolylsulfinyl)-N,N-dimethylacetamide · (MW 225.34)
Physical Data: [a]D = +194.7° (CHCl3, c = 1).
The Pummerer reaction of optically active (R)-(+)-a-(p-tolylsulfinyl)-N,N-dimethylacetamide with Acetic Anhydride in the presence of 1,3-Dicyclohexylcarbodiimide is highly stereoselective, affording the corresponding a-acetoxy sulfide in moderate yield but with nearly 70% ee (eq 2).3,4 The recovered starting sulfoxide is obtained in 63% yield.
Good asymmetric induction is also observed during the aldol-type condensation of the magnesium enolate of (R)-(+)-a-(p-tolylsulfinyl)-N,N-dimethylacetamide with aldehydes (eq 3).1,2
A model (1), similar to that proposed for aldol-type condensation of a-sulfinyl esters,5 has been proposed to predict the chirality of the resulting b-hydroxy amides.
Guy Solladié & Françoise Colobert
University Louis Pasteur, Strasbourg, France