The Chemistry of C₂‐Symmetric Bis(sulfoxides): A New Approach in Asymmetric Synthesis

Abstract

Synthesis -[118 refs.]. -(DELOUVRIE, B.; FENSTERBANK*, L.; NAJERA, F.; MALACRIA*, M.; Eur.

The Chemistry of C2-Symmetric Bis(sulfoxides): A New Approach in Asymmetric Synthesis

“…In acyclic series with ( S , S )‐ 8 , Solladié et al82 and we9 have found good yields and diastereoselectivities with aromatic and alkyl aldehydes. Based on the work of Solladié et al describing the condensation of the anion of the ( R )‐ tert ‐butyl ( p ‐tolylsulfinyl)acetate with carbonyl derivatives,83 we have proposed the model displayed in Scheme .…”

“…This was first accomplished by Aggarwal et al using a water‐soluble DCC variant reagent (morpho CDI 82 ) to transform the formaldehyde‐alkylated bis(sulfoxide) 81 into methylenebis(sulfoxide) 83 (Scheme ) 86. This reaction proved also adequate for the preparation of acyclic derivatives 84 from the alcohol mixture of 72 + 73 9. Another report by Carretero et al87 mentions the synthesis of the ( S , S )‐1,1‐bis(ethoxycarbonyl)‐2,2‐bis( p ‐tolylsulfinyl)ethene ( 86 ), in a two‐step sequence involving first a quantitative condensation with oxomalonate, followed by a dehydration of 85 with DEAD.…”

“…However, some cases of low diastereoselectivity also suggested that the presence of a second sulfinyl group could be helpful to rigidify the reacting system and thus enhance the diastereoselectivities. This led us naturally to the use of various alkylidene bis(sulfoxides), for which we have recently proposed a new synthesis 9. This work is presented below (section II.5) and we are currently in the process of involving these promising compounds in a series of new applications.…”