100791-78-4Relevant articles and documents
Tartaric Acid, an Efficient Chiral Auxiliary: New Asymmetric Synthesis of 2-Alkyl-2-arylacetic Acids
Castaldi, Graziano,Cavicchioli, Silvia,Giordano, Claudio,Uggeri, Fulvio
, p. 3018 - 3027 (2007/10/02)
A highly enantioselective synthesis of 2-alkyl-2-arylacetic acids, an important class of antiinflammatory agents, based on a new diastereoselective α-bromination of homochiral acetals 1 and on the stereospecific silver-promoted rearrangement of the corresponding homochiral α-bromo acetals 2 and 3, is reported.The new methodology represents a meaningful example of the use of tartaric acid as efficient and economic chiral auxiliary.The asymmetric bromination of 1 is of general character and occurs with very high diastereoselectivity, even at room temperature; a mechanism for the new reaction is proposed.The overall process has been successfully applied to the preparation of enantiomerically pure 2-alkyl-2-arylacetic acids, among them (2S)-(+)-2-(6-methoxy-2-naphthyl)propanoic acid (Naproxen)